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María Palomares,
Alicia Delicado,
Elena Mansilla,
María Luisa de Torres,
Elena Vallespín,
Luis Fernandez,
Victor Martinez-Glez,
Sixto García-Miñaur,
Julián Nevado,
Fernando Santos Simarro, [......],
Elga F Belligni,
María Luisa Martínez-Fernández,
Eva Bermejo, Beata Nowakowska,
Anna Kutkowska-Kazmierczak,
Ewa Bocian,
Ewa Obersztyn,
María Luisa Martínez-Frías,
Raoul C M Hennekam,
Pablo Lapunzina
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ABSTRACT: We report eight unrelated individuals with intellectual disability and overlapping submicroscopic deletions of 8q21.11 (0.66-13.55 Mb in size). The deletion was familial in one and simplex in seven individuals. The phenotype was remarkably similar and consisted of a round face with full cheeks, a high forehead, ptosis, cornea opacities, an underdeveloped alae, a short philtrum, a cupid's bow of the upper lip, down-turned corners of the mouth, micrognathia, low-set and prominent ears, and mild finger and toe anomalies (camptodactyly, syndactyly, and broadening of the first rays). Intellectual disability, hypotonia, decreased balance, sensorineural hearing loss, and unusual behavior were frequently observed. A high-resolution oligonucleotide array showed different proximal and distal breakpoints in all of the individuals. Sequencing studies in three of the individuals revealed that proximal and distal breakpoints were located in unique sequences with no apparent homology. The smallest region of overlap was a 539.7 kb interval encompassing three genes: a Zinc Finger Homeobox 4 (ZFHX4), one microRNA of unknown function, and one nonfunctional pseudogen. ZFHX4 encodes a transcription factor expressed in the adult human brain, skeletal muscle, and liver. It has been suggested as a candidate gene for congenital bilateral isolated ptosis. Our results suggest that the 8q21.11 submicroscopic deletion represents a clinically recognizable entity and that a haploinsufficient gene or genes within the minimal deletion region could underlie this syndrome.
The American Journal of Human Genetics 08/2011; 89(2):295-301. · 10.60 Impact Factor
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ABSTRACT: Alpha-thalassemia/mental retardation syndrome (ATR-X) is a neurodevelopmental disorder with characteristic clinical picture as well as presence of pathognomonic haemoglobin H inclusions (HbH) on peripheral blood examination. Typical features of this condition are: severe intellectual impairment, muscular hypotonia, delay of growth, genitourinary/skeletal abnormalities and characteristic facial dysmorphism. Molecular basis of the syndrome constitute mutations in ATR-X gene located on the long arm of X chromosome (Xq13). In this work, clinical characteristics of the molecularly confirmed case of ATR-X syndrome in two brothers are presented. The mother of both affected boys is an asymptomatic mutation carrier. In one of the brothers additional studies revealed the presence of de novo 1q21.1 microdeletion. ATR-X syndrome symptomatology, differential diagnostics issues as well as the aims of genetic counselling are described.
Medycyna wieku rozwojowego 01/2011; 15(4):437-44.
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Nicola Brunetti-Pierri,
Jonathan S Berg,
Fernando Scaglia,
John Belmont,
Carlos A Bacino,
Trilochan Sahoo,
Seema R Lalani,
Brett Graham,
Brendan Lee,
Marwan Shinawi, [......],
Sayed Naqvi,
Adolfo D Garnica,
Saunder M Bernes,
Chin-To Fong,
Anne Summers,
W David Walters,
James R Lupski,
Pawel Stankiewicz,
Sau Wai Cheung,
Ankita Patel
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ABSTRACT: Chromosome region 1q21.1 contains extensive and complex low-copy repeats, and copy number variants (CNVs) in this region have recently been reported in association with congenital heart defects, developmental delay, schizophrenia and related psychoses. We describe 21 probands with the 1q21.1 microdeletion and 15 probands with the 1q21.1 microduplication. These CNVs were inherited in most of the cases in which parental studies were available. Consistent and statistically significant features of microcephaly and macrocephaly were found in individuals with microdeletion and microduplication, respectively. Notably, a paralog of the HYDIN gene located on 16q22.2 and implicated in autosomal recessive hydrocephalus was inserted into the 1q21.1 region during the evolution of Homo sapiens; we found this locus to be deleted or duplicated in the individuals we studied, making it a probable candidate for the head size abnormalities observed. We propose that recurrent reciprocal microdeletions and microduplications within 1q21.1 represent previously unknown genomic disorders characterized by abnormal head size along with a spectrum of developmental delay, neuropsychiatric abnormalities, dysmorphic features and congenital anomalies. These phenotypes are subject to incomplete penetrance and variable expressivity.
Nature Genetics 12/2008; 40(12):1466-71. · 35.53 Impact Factor
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Nicola Brunetti-Pierri,
Jonathan S Berg,
Fernando Scaglia,
John Belmont,
Carlos A Bacino,
Trilochan Sahoo,
Seema R Lalani,
Brett Graham,
Brendan Lee,
Marwan Shinawi, [......],
Sayed Naqvi,
Adolfo D Garnica,
Saunder M Bernes,
Chin-To Fong,
Anne Summers,
W David Walters,
James R Lupski,
Pawel Stankiewicz,
Sau Wai Cheung,
Ankita Patel
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ABSTRACT: Chromosome region 1q21.1 contains extensive and complex low-copy repeats, and copy number variants (CNVs) in this region have recently been reported in association with congenital heart defects
Nature Genetics 11/2008; 40(12):1466-1471. · 35.53 Impact Factor
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ABSTRACT: Complex chromosome rearrangements (CCRs) are rare structural abnormalities that involve at least two chromosomes and more than two breakpoints and are often associated with developmental delay, mental retardation, and congenital anomalies. We report on a de novo, apparently balanced translocation t(1;5;7)(p32.1;q14.3;p21.3) involving three chromosomes in a 7-year-old boy with severe psychomotor retardation, neonatal muscular hypertonia, congenital heart defect, polysyndactyly of hands and feet, and dysmorphic features resembling Greig cephalopolysyndactyly syndrome. Analysis of the chromosome breakpoints using fluorescence in situ hybridization (FISH) with locus-specific BAC clones and long-range PCR products did not identify chromosome imbalance at any of the interrogated regions. High-resolution comparative genomic hybridization (HR-CGH) and array CGH (aCGH) revealed two additional cryptic de novo deletions, del(1)(p31.1p31.1) and del(7)(p14.1p14.1), respectively, that are not associated with the translocation breakpoints. FISH and polymorphic marker analyses showed that the deletion on derivative chromosome 1 is between 4.2 and 6.1 Mb, and the deletion on derivative chromosome 7 is approximately 5.1 Mb, and that both are paternal in origin. The deletion on chromosome 7p encompasses the GLI3 gene that is causative for the Greig cephalopolysyndactyly, Pallister-Hall and some cases of Acrocallosal syndromes. We discuss the potential mechanisms of formation of the described CCR.
American Journal of Medical Genetics Part A 12/2007; 143A(22):2738-43. · 2.39 Impact Factor
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ABSTRACT: The underlying genetic cause of mental retardation (MR) remains unknown in about half of the cases. Recently, using whole genome array comparative genomic hybridization (array-CGH), submicroscopic genetic imbalances have been detected in up to 20% of patients with an unexplained MR, dysmorphic features, and apparently normal karyotype. Here, we present a 12-year-old girl with features of basal cell nevus syndrome (BCNS), pulmonary valve stenosis, and MR, in whom array-CGH identified a 7.7 Mb deletion on 9q22.1-q22.32. The deleted region includes, among others, the ROR2 and PTCH genes. Haploinsufficiency of PTCH causes the BCNS syndrome and mutations in ROR2 have been found in an autosomal recessive Robinow syndrome and a dominantly inherited brachydactyly type 1B. We speculate that haploinsufficiency of ROR2 may contribute to pulmonary valve stenosis. Because of an age-dependent penetrance, BCNS may be challenging for diagnosis particularly when the features are not part of a typical clinical spectrum of BCNS. Early diagnosis of BCNS is important for preventing the development of associated tumors and better care of the patient. Our data confirm the previous observations that application of the whole genome array-CGH should be considered in selected patients with undiagnosed MR and dysmorphic features.
American Journal of Medical Genetics Part A 09/2007; 143A(16):1885-9. · 2.39 Impact Factor
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ABSTRACT: The underlying genetic cause of mental retardation (MR) remains unknown in about half of the cases. Recently, using whole genome array comparative genomic hybridization (array-CGH), submicroscopic genetic imbalances have been detected in up to 20% of patients with an unexplained MR, dysmorphic features, and apparently normal karyotype. Here, we present a 12-year-old girl with features of basal cell nevus syndrome (BCNS), pulmonary valve stenosis, and MR, in whom array-CGH identified a 7.7 Mb deletion on 9q22.1–q22.32. The deleted region includes, among others, the ROR2 and PTCH genes. Haploinsufficiency of PTCH causes the BCNS syndrome and mutations in ROR2 have been found in an autosomal recessive Robinow syndrome and a dominantly inherited brachydactyly type 1B. We speculate that haploinsufficiency of ROR2 may contribute to pulmonary valve stenosis. Because of an age-dependent penetrance, BCNS may be challenging for diagnosis particularly when the features are not part of a typical clinical spectrum of BCNS. Early diagnosis of BCNS is important for preventing the development of associated tumors and better care of the patient. Our data confirm the previous observations that application of the whole genome array-CGH should be considered in selected patients with undiagnosed MR and dysmorphic features. © 2007 Wiley-Liss, Inc.
American Journal of Medical Genetics Part A 07/2007; 143A(16):1885 - 1889. · 2.39 Impact Factor
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Zhishuo Ou,
Małgorzata Jarmuz,
Steven P Sparagana,
Jacques Michaud,
Jean-Claude Décarie,
Svetlana A Yatsenko, Beata Nowakowska,
Patti Furman,
Chad A Shaw,
Lisa G Shaffer,
James R Lupski,
A Craig Chinault,
Sau W Cheung,
Paweł Stankiewicz
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ABSTRACT: We report clinical findings and molecular cytogenetic analyses for two patients with translocations [t(14;17)(p12;p12) and t(15;17)(p12;p13.2)], in which the chromosome 17 breakpoints map at a large low-copy repeat (LCR) and a breakage-prone TRE-2 (USP6) oncogene, respectively. In family 1, a 6-year-old girl and her 5-year-old brother were diagnosed with mental retardation, short stature, dysmorphic features, and Charcot-Marie-Tooth disease type 1A (CMT1A). G-banding chromosome analysis showed a der(14)t(14;17)(p12;p12) in both siblings, inherited from their father, a carrier of the balanced translocation. Chromosome microarray and FISH analyses revealed that the PMP22 gene was duplicated. The chromosome 17 breakpoint was mapped within an approximately 383 kb LCR17pA that is known to also be the site of several breakpoints of different chromosome aberrations including the evolutionary translocation t(4;19) in Gorilla gorilla. In family two, a patient with developmental delay, subtle dysmorphic features, ventricular enlargement with decreased periventricular white matter, mild findings of bilateral perisylvian polymicrogyria and a very small anterior commissure, a cryptic duplication including the Miller-Dieker syndrome region was identified by chromosome microarray analysis. The chromosome 17 breakpoint was mapped by FISH at the TRE-2 oncogene. Both partner chromosome breakpoints were mapped on the short arm acrocentric heterochromatin within or distal to the rRNA cluster, distal to the region commonly rearranged in Robertsonian translocations. We propose that TRE-2 together with LCR17pA, located approximately 10 Mb apart, also generated the evolutionary gorilla translocation t(4;19). Our results support previous observations that the USP6 oncogene, LCRs, and repetitive DNA sequences play a significant role in the origin of constitutional chromosome aberrations and primate genome evolution.
Human Genetics 10/2006; 120(2):227-37. · 5.07 Impact Factor
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ABSTRACT: We present a family with three cases of recombination aneusomy rec(5)dup(5q) originating from a large parental pericentric inversion of chromosome 5. The proband--a 6-year-old girl with mental retardation, speech delay, microcephaly, and slight facial dysmorphism--was referred for subtelomere testing. FISH with a Multiprobe Chromoprobe T System (CytoCell) and with several BAC clones mapping to both subtelomere regions of chromosome 5, revealed a recombinant chromosome rec(5)dup(5q) originating from a paternal pericentric inversion inv(5)(p15.33q35.3). The same inversion was present in the proband's father's twin-brother and rec(5)dup(5q) was also identified in his two mentally retarded daughters. The distance of breakpoints from the telomere was: 0.234-1.4 Mb for 5p and 4.1-4.8 Mb for 5q. HR-CGH analysis confirmed the duplication of the 5q subtelomeric region but did not identify any concomitant deletion in the 5p subtelomere. Precise mapping of the aneusomic regions in the proband enabled mapping the cat cry and speech delay to 5p15.33, making the earlier localizations of these features more precise. Our family shows that the large pericentric inversion with both breakpoints at subtelomeric regions of chromosome 5 is associated with a high risk of rec(5)dup(5q) in the progeny.
Journal of applied genetics 02/2005; 46(1):109-14. · 1.66 Impact Factor
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ABSTRACT: Until recently, great variety of marker chromosomes and difficulties with their identification have presented a problem for cytogenetic and clinical interpretation of the karyotype. At present, molecular cytogenetic methods of chromosome analysis enable precise characterization of such abnormalities providing knowledge necessary for estimation of their genetic risk.
The aim of the study was molecular cytogenetic characterization of marker chromosomes recognized in three patients, an analysis of clinical features in relation to the abnormality and estimation of genetic risk of identified markers.
Karyotypes of three phenotypically abnormal patients were estimated in lymphocytes from peripheral blood by G banding analysis. Marker chromosomes were identified by fluorescence in situ hybridization (FISH), multiplex FISH, multicolor band and high resolution comparative genomic hybridization methods.
Marker chromosomes were identified as inv dup(22)(pter->q11.2::q11.2->pter), der(8)(:p22->q11.2:), der(2l)(:pter->q21.3:) and der(19)(:p11->q13.1). All of them contained euchromatic sequences. First marker, an inverted duplication of chromosome 22q11.2 corresponding to tetrasomy of this chromosome region was recognized in a child with partial cat eye syndrome. Two further markers derived from chromosomes 8 and 21 were found in a child with mosaic karyotype and clinical features of trisomy 8p. In the third case additional chromosome material was derived from chromosome 19 and it was found in a patient with mild mental retardation and clinical features of ovary dysgenesis. Genetic risk of identified marker chromosomes except for mar(19) was estimated as high.
Our results provide further evidence for diagnostic value of molecular cytogenetic methods. They also confirmed the general opinion of the high risk of phenotypic abnormalities in the carriers of marker chromosomes containing euchromatic sequences.
Medycyna wieku rozwojowego 10(1 Pt 2):211-25.
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ABSTRACT: In about 6% of individuals with intellectual disability, dysmorphic features and congenital anomalies, an abnormal, apparently balanced karyotype is found. These abnormalities may result from abnormal expression of genes at the breakpoints, presence of a submicroscopic deletion, or other unbalanced chromosome aberrations. In such cases, the detailed analysis of breakpoints of balanced chromosome rearrangements may help with identification of genes responsible for patient's clinical features.
Was the explanation of causes of abnormal phenotype in the carriers with abnormal but balanced karyotype.
Cytogenetic-molecular analysis performed in nine patients with mental retardation, dysmorphic features and congenital anomalies. Studies with subtelomeric probes, high resolution comparative genomic hybridization (HR-CGH) and fluorescence in situ hybridization (FISH) with region-specific BAC clones were performed.
Seventeen chromosome breakpoint regions were narrowed to 200-400 kb. In one case, an 0.5-Mb submicroscopic deletion associated with more complex rearrangement has been found. Mapping of the breakpoints and information obtained from the UCSC Human Genome Browser data base enabled identification of 46 genes in these regions. Twelve genes, that may have been disrupted as a result of the patients' chromosomal rearrangement, were found. At four different breakpoints the identified genes (NRCAM, NPTX1, NMT1, MAPT, HDAC5 and MEF2C) may be due to a position effect.
The results confirm earlier suggestions concerning reasons of abnormal phenotype in the patients with balanced chromosome rearrangements and present the value of detailed analysis of the genome in such cases.
Medycyna wieku rozwojowego 10(1 Pt 2):227-46.
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ABSTRACT: Cytogenetics analysis is at present the basic element of the diagnostic process of genetic disorders which are caused by chromosomal abnormalities. Since the chromosome banding technique has been introduced in the 1970s, it has been available as a diagnostic tool of a number of clinical syndromes. It enabled to prove the causal association between specific chromosomal abnormalities and clinical features observed in patients. However, since banding resolution is not always sufficient for the identification of chromosomal abnormalities, additional techniques for solving diagnostic dilemma of classical cytogenetics are needed. A new field of cytogenetics -- molecular cytogenetics, the product of a combination of cytogenetics and molecular biology, has increased the resolution and diagnostic utility of cytogenetic analysis. The basic method of molecular cytogenetics is fluorescence in situ hybridization (FISH). It enables a specific detection of unique sequences, chromosomal regions or entire chromosomes in metaphase, interphase cells or in tissue sections. In this article FISH technique and its modifications such as multicolor FISH (M-FISH, SKY, CCK), Primed In Situ Labelling (PRINS) and Comparative Genomic Hybridization (CGH) are presented. The range of applications and the use of these techniques for the identification of chromosomal abnormalities in relation to diagnostic possibilities of the classical methods of karyotyping is also discussed.
Medycyna wieku rozwojowego 8(1):7-24.
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ABSTRACT: In approximately 6% of balanced chromosomal rearrangements carriers, intellectual disability, dysmorphic features and congenital anomalies can be found. The abnormal phenotype might be the result of genomic imbalance or aberrant expression caused by direct breakage of a dosage sensitive gene.
To estimate the frequency and implication of the submicroscopic chromosomal aberrations on the abnormal phenotypes present in patients with balanced chromosomal rearrangements. Also an attempt was made to define the type of genetic defect and gene identification responsible for the intellectual disability and additional clinical features.
22 patients with intellectual disability, congenital anomalies and dysmorphic features were analysed. Molecular karyotyping was performed in all patients using FISH with region-specific BAC clones, high resolution comparative genomic hybridization (HR-CGH) or array CGH (aCGH). A targeted or whole genome microarrays were applied.
In 5 of 22 carriers 6 microdeletions and one duplication were found (7/22, 31.8%). Only two microdeletions were mapped at the chromosomal breakpoints. Three rearrangements had more complex structure than conventional methods demonstrated. In the chromosomal breakpoints of 21 patients the 24 genes, which functions suggest the relationship between abnormal gene expression and patients' intellectual disability, were mapped.
We showed that in a considerable group of patients with balanced chromosomal rearrangements and abnormal phenotype the cryptic aberrations, unidentified by conventional methods, are present. These results confirmed the legitimacy of detailed analysis of the chromosomal breakpoints as well as the whole genome screening with the use of new cytogenetic methods.
Medycyna wieku rozwojowego 13(2):81-93.
