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Red Hair: A Mutation, A Royal Trait, and Sometimes a Curse (Sheikh 2009)

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Sheikh A, Rashidul A. Red Hair: A Mutation, A Royal Trait, and Sometimes a Curse. Montgomery College Student Journal of Science and Mathematics. 2009;5. Supervised by R Alam.
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Red Hair: A Mutation, A Royal Trait, and
Sometimes a Curse
by
Aminah Sheikh
Supervised by
Dr. Rashid Alam
Of all the races on this earth, the Celtic are extremely well known for having one of
the most captivating hair colors known to man, red. From mysterious and alluring, to fiery
and powerful, this hair color captures the attention of people all over the world. Until about
a decade ago, we did not know what exactly caused this hair color to emerge into our
society however, this did not keep us from wondering why. From the artwork of
Michelangelo, to the present day media attention of redheaded British Royalty, red hair
color always had a significant position in our society. Thanks to the work of Roger Cone,
Jonathan Rees, and other distinguished scientists, we now know that the physical
manifestation of this hair color is because of a mutation in a gene on chromosome sixteen,
and not having originated from the Neanderthals.
Generally, hair color is determined by a substance called melanin. This is produced
by melanocytes, a group of specialized cells near the hair bulb (Sustaita). There are two
types of melanin, eumelanin and phaeomelanin, and the ratios of these pigments are what
determine hair color. Brown to black hair color is produced by a high amount of eumelanin
pigment and a little amount of phaeomelanin. Red hair color is produced by a high amount
of phaeomelanin, and a little amount of eumelanin pigment, while blond hair is produced
by little amounts of both pigments (Red Hair Genetics).
There are two genes responsible for the production of hair color, the melanocortin-1
receptor gene (
MC1R
gene) and the pro-opimelanocortin gene (
POMC
gene). The
MC1R
gene is located on chromosome 16, the long arm, section 24, subsection 3, and it provides
instructions for creating a gene product, the receptor for the alpha-melanocyte-stimulating
hormone (α-MSH) (Genetics Home Reference). The
POMC
(pro-opiomelanocortin) gene
produces peptide products yielding a few hormones, one of which is the α-MSH. This α-
MSH is produced in the pituitary gland of the brain and binds to an extracellular
melanocortin-1 receptor which is located in the plasma membrane. By the binding of this
hormone to the outside of the receptor, the receptor becomes activated and its result
shows up in the melanocytes. Although the MC1R is one of 5 possible receptors, the MC1R
is the main receptor for α-MSH (Millington).
The melanocortin-1 receptor belongs to a class of protein receptors known as the G-
protein-coupled receptors (GPCRs). These receptors make up the largest and most diverse
families of proteins (Kroeze, Sheffler and Roth). They are located on the plasma membrane
and communicate between the external and internal environments of the cell. Each
receptor is activated by the binding of its specific ligand to the receptor’s active site. This
causes the protein to become activated and release some specific components inside the
cell for the activation of a specific cellular mechanism (Filmore). According to an article
from the
Journal of Cell Science
, scientists claim that “Depending on the type of G protein to
which the receptor is coupled, a variety of downstream signaling pathways can be
activated…” (Kroeze, Sheffler and Roth). This family of proteins is so incredibly diverse
because each receptor has to stay independent in order to prevent conflicting signals with
other receptors.
In a properly functioning
MC1R
gene, the melanocortin-1 receptor receives the α-
MSH and sends signals to stimulate chemical reactions inside the melanocytes that produce
the dark pigment, eumelanin (Genetics Home Reference). The general chemical pathway
for the production of the eumelanin pigment is as follows: α-MSH, MC1R, cAMP, Tyrosine,
Dopaquinone, and then either the chemicals for phaeomelanin or eumelanin (Rees and Ha
M.D, Melanocortin-1 receptor: What's red got to do with it?).
When the melanocortin-1 receptor is activated, the cyclic adenosine monophosphate
(cAMP) concentration inside the melanocytes is elevated, resulting in the activation of the
eumelanin pathway (Figure 1). Specifically, the synthesis of eumelanin producing enzymes
is elevated due to the increased levels of cAMP inside the melanocytes. The dark or black
pigments that are synthesized by the enzymes are then combined with proteins forming
eumelanosomes. Then, these eumelanosomes get deposited in the hair as dark or black
pellets (Filmore; Figure 2). In a mutated melanocortin-1 receptor, the α-MSH is unable to
bind to the receptor resulting in the activation of the default phaeomelanin pathway. In
heterozygotes, one allele is active and the other allele is inactive. Because of this, half of the
receptors are activated for the production of eumelanin pigments and the other half
undergo activation for the default phaeomelanin pigments. Therefore, both pigments are
found. Although the
MC1R
gene is a key gene in human pigmentation, researchers also
believe that there are other genes that contribute to the outcome of a person’s hair and skin
color (Genetics Home Reference). Therefore, it is important to keep in mind that
MC1R
is
the main determining factor of producing red hair, but it is not the only one.
Source: Gene Assist Pathway Atlas.
Figure 1: The signal transduction pathways for the production of hair color. Activation of
MC1R by α-MSH elevates cyclic-AMP levels in the melanocytes. With the presence of cyclic-
AMP, the transcription and translation of the enzyme required for the production of
eumelanin pigment are enhanced. Therefore, the melanogenic enzymes synthesize
eumelanin. However, when the receptor is mutated and not activated, the phaeomelanin
pigment is produced by default.
Source: University of Alabama.
Figure 2: In the presence of the melanogenic enzymes, the biochemical pathway for
synthesis of eumelanin is activated. Without these enzymes, the default pathway for the
synthesis of phaeomelanin is preferred.
In 1995, this
MC1R
gene in humans was discovered by Jonathan L. Rees, professor at
the University of Edinburgh,
et al
. However before Jonathan L. Rees
et al
., Roger Cone
et al
.
were first to clone the
MC1R
gene in mice in 1993. From their work, they concluded that
some of the mutations concerned meant that MC1R did not work. Since these mice served
Melanogenic Enzymes
as models for human red hair, scientists were able to apply Cone’s research to human
genetics. (Rees and Ha M.D, Melanocortin-1 receptor: What's red got to do with it?) From
this, scientists concluded that the receptor did not work in humans as well, in order for the
red hair phenotype to develop.
Specifically, the red hair color is caused by loss of function mutations for the
melanocortin-1 receptor gene (
MC1R
gene). This gene has an autosomal recessive mode of
inheritance and in order for one to develop the red hair phenotype, one needs to have both
copies of the
MC1R
gene to be mutated (Rees, Healy and Jordan). There are five mutations
that are the most commonly associated with red hair: Asp84Glu, Arg142His, Arg151,
Arg160Trp, and Asp294His (Mumm and Draznin M.D). Each mutation is referred to as a
variant and, for example, Asp84Glu means that the amino acid aspartate is replaced by the
amino acid glutamate at codon 84. Each codon is a triplet of nucleotide bases in the
messenger RNA (messenger ribonucleic acid). If the receptor is mutated, it produces an
alternative version of the protein and cannot bind to the α-MSH. From this mechanism, the
eumelanin pathway is still slightly activated to produce a very low concentration of
eumelanin pigment. However, since the receptor is mainly not active, the default
phaeomelanin pathway is greatly activated to produce phaeomelanin pigment at a higher
concentration, thus producing red hair. It is the ratio of the higher amount of
phaeomelanin pigment to eumelanin pigment that produces red hair color and not black.
Melanocytes have a way of recycling the receptor that is activated and bound to α-
MSH. This occurs by the cytoplasmic protein β-arrestin binding to the activated receptor,
which ends up “turning off” the G-protein-coupled receptor. This arrestin-receptor complex
enters the cell via endocytosis which in turn causes the ligand to be removed, and the
receptor to be recycled back to the membrane (Filmore). However, if the receptor is not
activated, there will be no recycling of the receptor back to the membrane because there
will be no ligand to be removed.
From the development of red hair comes the fear of developing skin cancer as well.
Because of the mutations in the
MC1R
gene, the production of phaeomelanin can aid in the
development of skin cancer. Jonathan L. Rees,
et al
. showed that most redheads are
homozygous for many loss of function mutations. In addition, there also seemed to be a
clear dosage effect for heterozygotes, being intermediate between homozygous and wild-
type individuals for skin type, freckling, and shades of hair. In the case of skin, the carriers
(heterozygotes) can be at more of a risk of developing skin cancer, even if they do not have
red hair. Overall, the
MC1R
gene mutations are largely responsible for the most common
cancer in Caucasians (Rees and Ha M.D, Melanocortin-1 receptor: What's red got to do with
it?).
There are two theories behind why
MC1R
gene mutations have a higher probability
of leading to skin cancer. The first one is that eumelanin may be a better sunblock than
phaeomelanin. If there is less eumelanin, then the ultraviolet radiation photons may not be
blocked and will harmfully affect the epidermal cells. Another theory is that not necessarily
the absence of eumelanin, but the presence of phaeomelanin is directly harmful because it
is an ineffective sunblock and may produce dangerous effects when exposed to radiation.
Maria Teresa Landi, M.D., Ph.D., the lead study investigator at the National Cancer Institute
offers the following possibility: “One possibility is that people with
MC1R
variant forms and
variable pigmentation generate more reactive chemicals in their cells as a result of the
ultraviolet exposure in sunlight. These reactive chemicals can induce mutations, like those
in the
BRAF
gene, which may lead to cancer” (National Cancer Institute).
BRAF
genes, or
cancer-causing genes, are mutated when exposed to UV radiation and result in melanomas,
or tumors from cells which produce skin pigment, which can develop anywhere on the
body where these cells are present (National Cancer Institute).
Historically, because of the high amounts of sun exposure in Africa, having light skin
posed as a great threat to those living there so it was harder for this trait to emerge. ‘“We
don’t know with certainty when the first redheads walked the earth,’ Rees says. ‘But we
believe these changes arose in less time than we thought, maybe 20,000 to 40,000 years
ago’” (Derbyshire). From comparisons between chimpanzee and the human DNA
sequences, it was clarified that there was a large degree of functional constraints on the
MC1R
gene until migration out of Africa. Concepts like migration patterns are a part of
Population Genetics, “the subdiscipline that studies heredity in groups of individuals for
traits that are determined by one or only a few genes” (Russell). In general, there was
evidence of strong selection against skin lightening or red hair color, therefore mutations of
the gene were not “allowed to occur by evolution.” This way, it was very hard to see the
accumulations of these mutations. Then, the human population spread out of Africa and
caused the selective force against the redheads to be removed. From this, there were more
individuals with lighter hair color, eye color, and skin color. In the non-African populations,
especially in Europe, there was rapid development of mutations in this gene. Therefore,
this was because of many different significant changes, not just from a small group of
mutated individuals (Rees and Ha M.D, Melanocortin-1 receptor: What's red got to do with
it?).
Rees
et al
. also explained that the importance of being a redhead may have stemmed
from the “biologically materialistic position” concept, which is the conscious choice of mate
based upon appearance, status, or other similar perceptions. Overall, this may have affected
human evolution (Rees and Ha M.D, Melanocortin-1 receptor: What's red got to do with
it?). Conceptually, the phenotype of red hair was like that of a peacock’s tail. In the way of
attracting mates, these features were considered to be beautiful and at the time, red hair
was also quite a rare feature, hence the reason why it was considered to be such a desirable
trait.
In addition, it is believed that the redheads were selected against in Africa because
of the high levels of UV radiation, therefore causing a genetic drift to occur to Europe. In a
new genetic study, lead author Carles Lalueza-Fox, of the University of Barcelona stated
that, “In the cases of both Neanderthals and modern Europeans, the gene mutation that
caused fairer complexions spread only after the respective populations migrated from
Africa” (Handywerk). From this genetic drift, countries such as Scotland and Ireland are
known for the highest percentages of redheads in Europe.
It is difficult to narrow down when the mutations actually arose, but evolutionary
experts have argued that these mutations arose after ancestors of white Europeans moved
northward from Africa around 20,000 to 40,000 years ago. However, there is also a theory
that the red hair gene originated in the Neanderthals. “The idea was based on a claim that
the gene was at least 100,000 years old and so may have been present before modern man
left Africa. To pass into our DNA, our ancestors would have had to have interbred with
Neanderthals, an unfashionable theory among experts” (Nic & the Neanderthals). Although,
there are many theories, the more accepted one is that this trait did not come from
Neanderthals. From multiple studies, there is evidence that both modern humans and
Neanderthals both had mutations for the
MC1R
gene for red hair; however we did not
inherit this from Neanderthals. Scientist Holger Römpler of Harvard University discussed
their study: “‘The two Neanderthal individuals we studied showed a point mutation not
seen in modern humans’” (Harvard University). To make sure their point mutation was
legitimately from the Neanderthals they were studying, they checked about 3,700 people
for a specific point mutation of the
MC1R
gene. “None showed the mutation, suggesting that
Neanderthals and
Homo sapiens
followed different evolutionary paths to the same
redheaded appearance” (Harvard University). Therefore, although about one percent of
Neanderthals may have had red hair, we did not get this mutation from them.
Currently, Scotland holds the highest percentage of thirteen percent of redheads on
earth. Under Scotland is Ireland with ten percent, however, redheads are seen all over the
earth, even in Asia. Although Scotland and Ireland hold the highest percentages of
redheads, there are theories that red hair is not originally a Celtic trait, but that it came
from the Vikings. In about 795 A.D., the Vikings raided near Dublin and their red hair color
was passed down the generations when they started mating with the Irish (BBC). Eric the
Red was known for his red hair and so were many other Scandinavians. However, this is
not to say that the Scandinavians were the only reason for the Irish having their red hair.
They could have already had the mutation in their population, but in a small amount and so
when the Vikings invaded, the presence of redheads in the population increased
dramatically as a result of interbreeding. In the
2006 European Journal of Genetics
, there
was a study on Scandinavians and their impact on Irish genetics. From this, they found that
“…there is scant evidence of Scandinavian Y-chromosome introgression in a general Irish
population sample” (McEvoy, Brady and Moore). Although this study was based on forty-
seven Irish men, this is still quite accurate because “…the findings are consistent with a
relatively small number of Norse settlers (and descendants) migrating to Ireland during
the Viking period (ca. AD 800-1200)” (McEvoy, Brady and Moore). Therefore, the rumor
that the Irish owe their vibrant red hair to the Viking invasion seems false. The Vikings may
have had an impact on the number of redheads, but they are not the sole reason for the
emergence of red hair in Ireland.
From my own background, I have many relatives of Polish descent who have or had
red hair and it made me wonder why. In the past, I thought that the Celts were the ones
with red hair, so I wondered as to why my Polish relatives have red hair as well. From my
research, I found out that Poland was heavily populated with the Ashkenazic Jews, who are
also known for their red hair. In a 1990 article titled “Polish Jewish History,” the author
stated that “During the eighteenth century, at least, about half of the urban population of
Poland was Jewish” (Hundert). Therefore, it seems safe to say that they were Ashkenazic
Jews and not Sephardic Jews because they were from Poland. In an article titled, “On the
Racial Characteristics of Modern Jews,” researchers found that there were “…thrice as
many red-haired individuals as either Poles, Russians, or Austrians, and half as many again
as Germans.” Although this is quite an old article from 1886, it suggests to us the high
amount of red haired Jews in Europe. In addition, the article also makes the connection
between the Ashkenazic Jews and red hair. “…when it does occur among Ashkenazim of
North Europe, it is found more among Jews than in the indigenous population…” (Jacobs).
Therefore, the Ashkenazic Jews of Northern Europe, and especially in Poland, are unique
because of the high prevalence of red haired individuals in its population.
In many of these articles, red haired people were grouped together as being a part of
erythrism. This is a term describing those as having “exceptional prevalence of red
pigmentation” (as in skin or hair) (Merriam-Webster). In another article titled,
“Anthropology of the Jews,” the researchers claimed that erythrism is a characteristic of
European Jews. In addition, they claimed that red hair is not considered to be of recent
origin, and that “…it was not unknown among the ancient Hebrews, for Esau was said to
have been ‘red all over like a hairy garment’” (Fishberg). Thus, it seems that red hair has
been in our population for centuries and that the Celts are not the only ones known for
having this beautiful characteristic.
So far, many understand that the Celts could have inherited some of their red hair
color from the Vikings, but it seems that those of Jewish descent may also have contributed
to the accumulation of redheads, even in Scotland. According to the article titled “On the
Racial Characteristics of Modern Jews”, the researchers speculate that the Scottish could
have inherited their red hair from the European Jews. “Indeed, but for the abundant
presence of red hair among Scotchmen [
sic
] it might be more open to explain the origin of
red hair among Europeans as due to an infusion of Jewish blood than to account for it
among Jews by assuming intermixture with Aryans” (Jacobs). To say that this is possible
helps explain how Scotland is the country today that has the highest percentage of red
haired individuals, although the country is mainly Christian. However, there is also the
possibility of Jewish people changing their religion to Christianity, and the fact that there
might be Jewish heritage in the backgrounds of the Scots, but they just do not know it yet.
The whole topic of Ashkenazic Jews still requires more research and study, but this does
not falsify the archived research on the redheads of Europe.
Interestingly enough, there was a time where people in England tried to emulate the
redheaded royalty. Queen Elizabeth I had natural red hair and in the Elizabethan era, many
of the nobility tried to emulate her red hair (Alchin). It was considered fashionable to have
red hair and many women tried to make their hair just like that of Queen Elizabeth I. In
fact, the members of the English Royal family of the House of Tudor were all redheads and
the color red was tied to royal ceremonies (Douglas).
Like in Europe, the color red was also valued in Asia. In India, red symbolizes
fertility and purity, which is usually why Indian brides have red saris and lenghas (Smith).
Often, red is paired with gold in clothing because gold refers to wealth, therefore adding
importance to the red color. Also in Indian weddings, the women use henna on their skin
for mendhi art which produces a dark red color. Henna is a plant, that when crushed and
added to water can produce various shades of red on skin and hair. Nevertheless, natural
red hair is rarely, yet still found in Pakistan and other parts of Asia.
Also from my own background, my relatives and I use henna on our skin for
weddings and religious ceremonies. Years ago, I learned that henna can be added to hair as
well. The practice of adding henna to hair came later and it was primarily considered for
practical use, not necessarily as a fashion statement. Often when older people lose their
hair color, they use henna to dye their hair. Yet now, henna is often used as a fun and
natural way of adding red color to hair. It is a semi-permanent dye, but it is used because it
is a cheaper and more natural way of adding color. These traditions of mendhi art and
henna use in hair spread to Pakistan and are now often a part of wedding ceremonies and
religious holidays in the Indo-Pakistan area.
From fiery and determined, to romantic and passionate, redheads always seemed to
have captured the attention of others, but not always good attention. In the United
Kingdom, there is a term known as “gingerism” that refers to the bullying or harassment of
redheads. Even in British royalty, no one is ever safe from this gingerism. Prince Harry
claims that he was bullied ever since he was a child (Sky News). Some even consider
gingerism to be almost as bad as racism. This has gone even to the extent of causing a
family to move twice in order to avoid persecution because of their red hair (Rohrer). In
the past, redheads were known to be untrustworthy and evil. Red was the color of the devil
and women with red hair and green eyes were often killed because they were considered
to be witches in Germanic folk culture (Johansen). Often, there were redheads with green
eyes because the phaeomelanin responsible for the red hair is also responsible for green
eyes. Therefore, the electric combination of bright red hair and stunning green eyes were
often viewed as evil and demonic.
In famous paintings, red hair was also symbolic of sin. In Michelangelo’s Temptation,
Eve is depicted as having brown hair and she is being handed a red apple from a red haired
serpent woman. Then, Adam and Eve are thrown out of the Garden of Eden and Eve is
wearing red hair instead of brown (Johansen). In addition, at St. Paul’s Cathedral, Eve has
blonde hair beforehand. Then, Adam and Eve are driven from the Garden of Eden and it is
shown that she now has red hair and is cowering (Johansen). The red color in the apple, the
serpent woman, and Eve in the second fresco are all symbolic of evil and sin. Therefore, it is
not surprising that Michelangelo used this red color in his paintings because of the obvious
association of red and the devil.
Although there are articles that document high percentages of redheads, many
people are worried if they are here to stay because it is a recessive trait. Recently, there has
been a rumor about redheads becoming extinct in the future. Many news articles are
starting to make people wonder and in the
Seattle Times
, they claim that there will be no
more redheaded individuals by the year 2100. “The reason, according to scientists at the
independent institute in England…is that just 4 percent of the world's population carries
the red-hair gene. The gene is recessive and therefore diluted when carriers produce
children with people who have the dominant brown-hair gene” (Flanigan). Genetically, this
just does not make sense. As long as there are individuals who have the mutation to show
the red hair phenotype, or individuals as carriers of the mutation, there will be no
extinction of the red hair color. The only way one could think that this color will disappear
is if all of those with the red hair, or the carriers, stop breeding completely with others who
either have red hair, or are carriers of the mutation. Ethically, this would just not be
possible because humans will continue to breed with whomever they choose, and no one
would be able to control this aspect of our lives. Therefore, although these news articles do
provide scientists with more attention from the general public, this scare is just that and
nothing more. However, it is important to realize that it is definitely possible that there
may be a decrease in the number of redheaded progeny. Nevertheless, the vibrant, bold,
and fiery red color is here to stay in our human population.
Works Cited
Alchin, Linda K. "Elizabethan Hair Styles." 16 May 2005. Elizabethan Era. 20 December 2007
<http://www.elizabethan-era.org.uk/elizabethan-hair-styles.htm>.
BBC. "History of the Celts." 23 November 1999. bbc.co.uk. 24 December 2007
<http://www.bbc.co.uk/dna/h2g2/A207479>.
Britain Express; Ross, David. "Celtic Britain." Britain Express. 24 December 2007
<http://www.britainexpress.com/History/Celtic_Britain.htm>.
Derbyshire, David. "The Age." 4 November 2002. Nic & the Neanderthals. 15 August 2007
<http://www.theage.com.au/articles/2002/11/03/1036308205329.html>.
Douglas, Stephen. "Redhead Encyclopedia." 1996. Redhead Facts. 20 August 2007
<http://www.ocala.com/stagnant/redhead/facts.html?nocache=1>.
Filmore, David. "It's a GPCR world." Modern Drug Discovery (2004).
Fishberg, Maurice. "Physical Anthropology of the Jews II--Pigmentation." March 1903. JSTOR.
2 January 2008 <http://links.jstor.org/sici?sici=0002-
7294%28190301%2F03%292%3A5%3A1%3C89%3APAOTJI%3E2.0.CO%3B2-5>.
Flanigan, Robin L. "Will rare redheads be extinct by 2100? ." 9 May 2005. The Seattle Times. 21
August 2007
<http://seattletimes.nwsource.com/html/living/2002266852_redhair09.html>.
Gene Assist Pathway Atlas. "Pathway." 2007. Applied Biosystems. 15 August 2007
<http://www.ambion.com/tools/pathway/resized_images/Melanocyte%20Development%
20and%20Pigmentation.jpg >.
Genetics Home Reference. "MC1R- melanocortin-1 receptor (alpha melanocyte stimulating
hormone receptor)." 11 January 2008. Genetics Home Reference. 20 August 2007
<http://ghr.nlm.nih.gov/gene=mc1r>.
Handywerk, Brian. "Some Neandertals Were Pale Redheads, DNA Suggests." 27 October 2007.
National Geographic. 26 December 2007
<http://news.nationalgeographic.com/news/2007/10/071025-Neandertals-
Redheads.html>.
Harvard University. "Ancient DNA Reveals That Some Neanderthals Were Redheads." 26
October 2007. Science Daily. 26 December 2007
<http://www.sciencedaily.com/releases/2007/10/071025143311.htm>.
Hundert, Gershon David. "Polish Jewish History." October 1990. JSTOR. 2 January 2008
<http://links.jstor.org/sici?sici=0276-
1114%28199010%2910%3A3%3C259%3APJH%3E2.0.CO%3B2-3 >.
Jacobs, Joseph. "On the Racial Characteristics of Modern Jews." 1886. JSTOR: The Journal of
the Anthropological Institute of Great Britain and Ireland. 9 January 2008
<http://links.jstor.org/sici?sici=0959-
5295(1886)15%3C23%3AOTRCOM%3E2.0.CO%3B2-Z>.
Johansen, Elizabeth. "Red Hair Facts." 2005. 20 August 2007
<http://www.purgatory.net/kornelia/1603/red_hair_facts.htm>.
Kroeze, Wesley K, Douglas J Sheffler and Bryan L Roth. "G-protein-coupled receptors at a
glance." Journal of Cell Science (2003): 4867-4869.
McEvoy, Brian, et al. "The scale and nature of Viking settlement in Ireland from Y-chromosome
admixture analysis." 6 September 2006. European Journal of Human Genetics. 2 January
2008 <http://www.nature.com/ejhg/journal/v14/n12/full/5201709a.html>.
Merriam-Webster. "erythrism." 2008. Merriam-Webster's Medical Dictionary. 20 December
2007 <http://medical.merriam-webster.com/medical/erythrism>.
Millington, G. W. M. "Proopiomelanocortin (POMC): the cutaneous roles of its melanocortin
products and receptors." Clinical and Experimental Dermatology (2006): 407-412.
Mumm, Christina D and Michelle Draznin M.D. "Melanocortin-1 receptor: Loss of function
mutations and skin cancer." Dermatology Online Journal (2006).
National Cancer Institute. "National Cancer Institute." 29 June 2006. Scientists Identify an
Inherited Gene That Strongly Affects Risk for the Most Common Form of Melanoma. 23
December 2007 <http://www.cancer.gov/newscenter/pressreleases/MelanomaGenetics>.
"Red Hair Genetics." Dermatology at the University of Edinburgh. 13 August 2007
<http://www.derm.med.ed.ac.uk/06_teaching/redhairgen.htm>.
Rees, Jonathan L and Tom Ha M.D. "Melanocortin-1 receptor: What's red got to do with it?"
December 2001. Dermatology at the University of Edinburgh. 13 August 2007
<http://www.derm.med.ed.ac.uk/PDF/Whats%20red%20got%20to%20do%20with%20it.
pdf>.
Rees, Jonathan L, et al. "Functional variation of MC1R alleles from red-haired individuals."
Human Molecular Genetics (2001): 2397-2402.
Rohrer, Finlo. "Is gingerism as bad as racism? ." 6 June 2007. BBC News. 2 January 2008
<http://news.bbc.co.uk/1/hi/magazine/6725653.stm>.
Russell, Peter J. iGenetics. A Mendelian Approach. San Francisco: Benjamin Cummings, 2006.
Sky News. "Ginger Prince Claims He Is Bullied." 11 July 2007. Sky News. 2 January 2008
<http://news.sky.com/skynews/article/0,,30100-1274724,00.html>.
Smith, Kate. "India-- a Country of Symbolic Colors." 2008. Sensational Color. 3 January 2008
<http://www.sensationalcolor.com/content/view/1086/143/>.
Sustaita, Hilda. Topic 3: Chemical Composition of Hair. 18 August 2007
<http://www.texascollaborative.org/hildasustaita/module%20files/overview.htm>.
University of Alabama. "Skin Color." February 2005. Human Adaptability. 15 August 2007
<http://www.as.ua.edu/ant/bindon/ant475/Skincolor/SKINCOLOR.PDF>.
Williamson, Roland. "Who Were The "Celts"? ." 31 March 2003. Regia Anglorum. 24
December 2007 <http://www.regia.org/celts1.htm>.
... The aim of this study is to investigate whether "redheads" or "gingers", people with red hair, are at any increased risk or higher prevalence of depression and/or anxiety due to factors such as bullying, casual prejudice and negative associations in pop culture and the media (Sheikh & Alam 2011.;Weir & Fine-Davis 1989). ...
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Background: People with red hair account for just 1 to 2% of the population worldwide and suffer a degree of prejudice, particularly in the U.K. Aims: To investigate any relationship between hair colour and anxiety or depression, and to survey the experiences and opinions of people with red hair throughout the world. Method: 1742 people from 20 countries completed a survey including the HADS anxiety and depression scale, seven survey questions about experiences of bullying, and open ended questions about the representation of people with red hair in popular culture. Results from the HADS were compared between groups using t-tests and the survey and open ended questions were analysed qualitatively. Results: In this sample women with red hair in the U.S.A. were found to be less anxious and depressed on average while red haired men in the U.K. were found to be more anxious according the HADS scale, small effect sizes were observed. Possible explanations are discussed. There was found to be a high prevalence of bullying against people with red hair and dis-satisfaction with the role of entertainment media in portraying red haired people Conclusion and implications: People with red hair are at high risk of bullying victimisation and are depicted using negative stereotypes in popular culture. This may contribute to anxiety disorders and depression. Implications for government policy regarding education and hate crime laws are discussed. Further research should be carried out on adolescents, in the U.K. in particular to determine the relationship of hair colour to anxiety and depression using more appropriate measures.
... 54,55 Recent evidence has suggested that Neanderthals had a mutation of their melanocyte stimulating hormone receptor resulting in them being redheaded and having Celtic-like fair skin. 56,57 This is the likely explanation for why people in Northern Europe have skin types 1 and 2. c) Aging. It was observed that 7-dehydrocholesterol concentrations in human epidermis were inversely related to age (Fig. 38). ...
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Vitamin D is the sunshine vitamin that has been produced on this earth for more than 500 million years. During exposure to sunlight 7-dehydrocholesterol in the skin absorbs UV B radiation and is converted to previtamin D3 which in turn isomerizes into vitamin D3. Previtamin D3 and vitamin D3 also absorb UV B radiation and are converted into a variety of photoproducts some of which have unique biologic properties. Sun induced vitamin D synthesis is greatly influenced by season, time of day, latitude, altitude, air pollution, skin pigmentation, sunscreen use, passing through glass and plastic, and aging. Vitamin D is metabolized sequentially in the liver and kidneys into 25-hydroxyvitamin D which is a major circulating form and 1,25-dihydroxyvitamin D which is the biologically active form respectively. 1,25-dihydroxyvitamin D plays an important role in regulating calcium and phosphate metabolism for maintenance of metabolic functions and for skeletal health. Most cells and organs in the body have a vitamin D receptor and many cells and organs are able to produce 1,25-dihydroxyvitamin D. As a result 1,25-dihydroxyvitamin D influences a large number of biologic pathways which may help explain association studies relating vitamin D deficiency and living at higher latitudes with increased risk for many chronic diseases including autoimmune diseases, some cancers, cardiovascular disease, infectious disease, schizophrenia and type 2 diabetes. A three-part strategy of increasing food fortification programs with vitamin D, sensible sun exposure recommendations and encouraging ingestion of a vitamin D supplement when needed should be implemented to prevent global vitamin D deficiency and its negative health consequences.
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G-protein-coupled receptors (GPCRs) constitute a large and diverse family of proteins whose primary function is to transduce extracellular stimuli into intracellular signals. They are among the largest and most diverse protein families in mammalian genomes. On the basis of homology with rhodopsin,
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Red hair in humans is associated with variant alleles of the alphaMSH receptor gene, MC1R. Loss of MC1R function in other mammals results in red or yellow hair pigmentation. We show that a mouse bacterial artificial chromosome (BAC) which contains Mc1r will efficiently rescue loss of Mc1r in transgenic mice, and that overexpression of the receptor suppresses the effect of the endogenous antagonist, agouti protein. We engineered the BAC to replace the mouse coding region with the human MC1R sequence and used this in the transgenic assay. The human receptor also efficiently rescued Mc1r deficiency, and in addition, appeared to be completely resistant to the effects of agouti, suggesting agouti protein may not play a role in human pigmentary variation. Three human variant alleles account for 60% of all cases of red hair. We engineered each of these in turn into the BAC and find that they have reduced, but not completely absent, function in transgenic mice. Comparison of the phenotypes of alphaMSH-deficient mice and humans in conjunction with this data suggests that red hair may not be the null phenotype of MC1R.
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The precursor protein proopiomelanocortin (POMC) produces many biologically active peptides via a series of enzymatic steps in a tissue-specific manner, yielding the melanocyte-stimulating hormones (MSHs), corticotrophin (ACTH) and beta-endorphin. The gene for alpha-MSH is encoded for by the POMC gene, but alpha-MSH cannot be produced from POMC gene transcription and translation without these specific post-translational proteolytic steps taking place. The MSHs and ACTH bind to the extracellular G-protein-coupled melanocortin receptors (MCR), of which there are five subtypes. Two (MC1R and MC5R) show widespread cutaneous expression. ACTH and alpha-MSH bind to MC1R to influence both pigmentation and the immune system. MC5R regulates the sebaceous glands. Mutations in the MC1R gene lead to fair skin and red hair in humans, which is also seen with inactivating human POMC gene mutations. MC1R mutant receptor expression can also correlate with an increased incidence of the three commonest forms of skin cancer. Other mutations can occur in the POMC system or parallel interacting pathways, such as in prohormone convertase 1 and agouti signalling protein, a human homologue of murine agouti protein. However, they do not necessarily affect skin colour or function in humans, and further studies are needed to clarify these observations.
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The Vikings (or Norse) played a prominent role in Irish history but, despite this, their genetic legacy in Ireland, which may provide insights into the nature and scale of their immigration, is largely unexplored. Irish surnames, some of which are thought to have Norse roots, are paternally inherited in a similar manner to Y-chromosomes. The correspondence of Scandinavian patrilineal ancestry in a cohort of Irish men bearing surnames of putative Norse origin was examined using both slow mutating unique event polymorphisms and relatively rapidly changing short tandem repeat Y-chromosome markers. Irish and Scandinavian admixture proportions were explored for both systems using six different admixture estimators, allowing a parallel investigation of the impact of method and marker type in Y-chromosome admixture analysis. Admixture proportion estimates in the putative Norse surname group were highly consistent and detected little trace of Scandinavian ancestry. In addition, there is scant evidence of Scandinavian Y-chromosome introgression in a general Irish population sample. Although conclusions are largely dependent on the accurate identification of Norse surnames, the findings are consistent with a relatively small number of Norse settlers (and descendents) migrating to Ireland during the Viking period (ca. AD 800-1200) suggesting that Norse colonial settlements might have been largely composed of indigenous Irish. This observation adds to previous genetic studies that point to a flexible Viking settlement approach across North Atlantic Europe.
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We present a red-haired patient who came to our clinic seeking information regarding his predisposition to skin cancer. We discuss the receptor involved in hair color and the allelic variants that lead to red hair. These variants are often characterized by loss of function mutations, which lead to a predisposition to non-melanoma skin cancers, with relative risks reaching as high as a 6.7 in one study. Most concerning, however, is that some of these loss of function mutations may act synergistically with genetic mutations that cause familial melanomas. Thus, red haired patients with familial melanoma syndromes have a greater risk of melanoma than those patients with familial melanoma syndromes alone.
A Mendelian Approach
  • Peter J Russell
  • Igenetics
Russell, Peter J. iGenetics. A Mendelian Approach. San Francisco: Benjamin Cummings, 2006.