Article

Allele frequencies of hemojuvelin gene ( HJV ) I222N and G320V missense mutations in white and African American subjects from the general Alabama population

Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama.
BMC Medical Genetics (Impact Factor: 2.45). 12/2004; 5. DOI: 10.1186/1471-2350-5-29
Source: DOAJ

ABSTRACT Background
Homozygosity or compound heterozygosity for coding region mutations of the hemojuvelin gene (HJV) in whites is a cause of early age-of-onset iron overload (juvenile hemochromatosis), and of hemochromatosis phenotypes in some young or middle-aged adults. HJV coding region mutations have also been identified recently in African American primary iron overload and control subjects. Primary iron overload unexplained by typical hemochromatosis-associated HFE genotypes is common in white and black adults in Alabama, and HJV I222N and G320V were detected in a white Alabama juvenile hemochromatosis index patient. Thus, we estimated the frequency of the HJV missense mutations I222N and G320V in adult whites and African Americans from Alabama general population convenience samples.

Methods
We evaluated the genomic DNA of 241 Alabama white and 124 African American adults who reported no history of hemochromatosis or iron overload to detect HJV missense mutations I222N and G320V using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Analysis for HJV I222N was performed in 240 whites and 124 African Americans. Analysis for HJV G320V was performed in 241 whites and 118 African Americans.

Results
One of 240 white control subjects was heterozygous for HJV I222N; she was also heterozygous for HFE C282Y, but had normal serum iron measures and bone marrow iron stores. HJV I222N was not detected in 124 African American subjects. HJV G320V was not detected in 241 white or 118 African American subjects.

Conclusions
HJV I222N and G320V are probably uncommon causes or modifiers of primary iron overload in adult whites and African Americans in Alabama. Double heterozygosity for HJV I222N and HFE C282Y may not promote increased iron absorption.

Download full-text

Full-text

Available from: Ronald T Acton, Apr 06, 2015
1 Follower
 · 
120 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Multiple sclerosis (MS) is a disease that causes neurological dysfunction. Studies attempting to elucidate the role of genes in MS development may aid efforts to control the damage caused by the disease that affects two million people worldwide, e.g. improved diagnosis and treatment. Although the association of MS and genes has not been fully characterized the proposed genetic etiology has been supported by the observed association of MS with the Major Histocompatibility Complex (MHC), haplotype HLA-DRB1*1501, DRB5*0101, DQA1*0102, DQB1*0602. Iron, or rather the dysregulation thereof, has also been implicated as a precipitating factor in MS development. Considering the factors of iron dysregulation and the genes involved in iron regulation, this study aims to identify variation within genes involved in iron metabolism namely the high iron gene (HFE), solute-carrier family 40 (iron regulated transporter) member 1 gene (SLC40A1), hepcidin anti-microbial peptide (HAMP), cytochrome b reductase 1 (CYBRD1) and hemojuvelin (HJV). Screening of 40 patients (33 female, seven male; 33 Caucasian, seven Coloured) for each of the five genes was achieved by the Heteroduplex Single-Stranded Conformation Polymorphism (HEX-SSCP) technique. Semi-automated DNA sequencing allowed for verification and characterization of the variants detected. Results included identification of four novel variants present in only the Caucasian patient group, characterized as IVS4-53G→A (HFE) (one of 33 patients; 3%), IVS2-65delA (CYBRD1) (two of 32 patients; 6.3%), 3’UTR+26delACGTCACGTTTCAAAACTA (CYBRD1) (one of 31 patients; 3.2%) and 219delG (HJV) (two of 33 patients; 6%). In addition, a total of 15 previously described variants were identified (seven intronic and eight exonic) of which three were also prevalent in only the Caucasian patient group. This study aimed to investigate the differences ... Thesis (MSc (Genetics))--University of Stellenbosch, 2007.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The discovery of hemojuvelin and its association with juvenile hemochromatosis are important not only for the diagnostics of this rare severe disease but also for the understanding of the complex mechanism of iron metabolism regulation. Currently, the physiological role of hemojuvelin is obscure. Recent experimental and clinical studies indicate that hemojuvelin will probably be a regulator of hepcidin, similar to HFE and transferrin receptor 2. However, in contrast to transferrin receptor 2, which is relevant in the hepcidin response to changes in transferrin saturation, HFE and especially hemojuvelin seem to be involved in the inflammation-induced hepcidin expression. Hepcidin, generally accepted as a hormone targeting enterocytes and macrophages, decreases iron absorption from the intestinal lumen and iron release from phagocytes. This mechanism explains the central role of hepcidin and, indirectly, its regulator, hemojuvelin, in the pathogenesis of hemochromatosis but also in anemia of chronic disease. Further basic and clinical research is needed to uncover the details of hemojuvelin pathophysiology required for potential pharmacological interventions.
    Journal of Molecular Medicine 08/2005; 83(7):521-5. DOI:10.1007/s00109-005-0668-y · 4.74 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A number of genetic disorders can result in the accumulation of excess iron in the body. These causes of hereditary hemochromatosis include defects in genes encoding HFE, transferrin receptor 2, ferroportin, hepcidin, and hemojuvelin. Hepcidin, with its cognate receptor, ferroportin, has emerged as a central regulator of iron homeostasis; all of the known causes of hemochromatosis appear to prevent this system from functioning normally. The most common form of primary hemochromatosis is that caused by C282Y mutation of the HFE gene. This mutation is most prevalent among Northern Europeans. Although the frequency of the homozygous genotype is approximately 5 per 1000, the disease itself is quite rare because the clinical penetrance of the genotype is very low.
    Annual Review of Medicine 02/2006; 57:331-47. DOI:10.1146/annurev.med.57.121304.131310 · 15.48 Impact Factor