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Jeroen K J Van Houdt,
Beata Anna Nowakowska,
Sérgio B Sousa,
Barbera D C van Schaik,
Eve Seuntjens,
Nelson Avonce,
Alejandro Sifrim, Omar A Abdul-Rahman,
Marie-José H van den Boogaard,
Armand Bottani, [......],
Catheline Vilain,
Annick Vogels,
Emma Wakeling,
Dagmar Wieczorek,
Louise Wilson,
Orsetta Zuffardi,
Antoine H C van Kampen,
Koenraad Devriendt,
Raoul Hennekam,
Joris Robert Vermeesch
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ABSTRACT: Nicolaides-Baraitser syndrome (NBS) is characterized by sparse hair, distinctive facial morphology, distal-limb anomalies and intellectual disability. We sequenced the exomes of ten individuals with NBS and identified heterozygous variants in SMARCA2 in eight of them. Extended molecular screening identified nonsynonymous SMARCA2 mutations in 36 of 44 individuals with NBS; these mutations were confirmed to be de novo when parental samples were available. SMARCA2 encodes the core catalytic unit of the SWI/SNF ATP-dependent chromatin remodeling complex that is involved in the regulation of gene transcription. The mutations cluster within sequences that encode ultra-conserved motifs in the catalytic ATPase region of the protein. These alterations likely do not impair SWI/SNF complex assembly but may be associated with disrupted ATPase activity. The identification of SMARCA2 mutations in humans provides insight into the function of the Snf2 helicase family.
Nature Genetics 02/2012; 44(4):445-9, S1. · 35.53 Impact Factor
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Aravindhan Veerapandiyan, Omar A Abdul-Rahman,
Margaret P Adam,
Michael J Lyons,
Melanie Manning,
Karlene Coleman,
Lisa Kobrynski,
Deeksha Taneja,
Kelly Schoch,
Holly H Zimmerman,
Vandana Shashi
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ABSTRACT: Chromosome 22q11.2 deletion syndrome (22q11DS) is associated with numerous and variable clinical manifestations including conotruncal heart abnormalities, palatal anomalies, hypoparathyroidism, immune deficiency, and cognitive deficits. The clinical suspicion of this syndrome is often heightened by the presence of characteristic facial features. A previous report highlighted the under-diagnosis of this condition in African Americans, thought to be related to a paucity of typical facial features. We ascertained the largest cohort (n = 50) of African-American individuals with 22q11DS reported thus far, across five genetics centers in the United States and report on their facial and other phenotypic features. About 3/4 of our cohort has at least one dysmorphic facial feature. Auricular abnormalities, especially small ears, are the most common dysmorphic facial feature followed by nasal and ocular abnormalities. Skeletal findings are seen in about 2/3 of our cohort, higher than the typical frequency reported in 22q11DS. Cardiac anomalies, developmental delay, and palatal abnormalities are seen at a lower frequency in our cohort. Thus, it is evident that the features traditionally associated with 22q11DS are difficult to recognize in African-American individuals with this syndrome, due to both altered frequencies of major anomalies and a non-classic facial appearance. Therefore, a high index of suspicion is needed to recognize 22q11DS in African-American individuals.
American Journal of Medical Genetics Part A 09/2011; 155A(9):2186-95. · 2.39 Impact Factor
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ABSTRACT: Haploinsufficiency of RASA1, located on chromosome 5q14.3, has been identified as the etiology underlying the disorder capillary malformation-arteriovenous malformation (CM-AVM). Recently, haploinsufficiency of MEF2C, located 1.33 Mb distal to RASA1 on chromosome 5q14.3, has been implicated as the genetic etiology underlying a complex array of deficits including mental retardation, hypotonia, absent speech, seizures, and brain anomalies. Here we report a patient who is haploinsufficient in both RASA1 and MEF2C who presents with dermatologic and neurologic abnormalities that constitute a 5q14.3 neurocutaneous syndrome. This finding highlights the need to assess for CM-AVM in patients with neurologic features consistent with MEF2C haploinsufficiency, and vice versa.
American Journal of Medical Genetics Part A 07/2011; 155A(7):1640-5. · 2.39 Impact Factor
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ABSTRACT: Sjögren-Larsson syndrome (SLS) is an autosomal recessive disorder characterized by ichthyosis, mental retardation, spasticity and mutations in the ALDH3A2 gene for fatty aldehyde dehydrogenase, an enzyme that catalyzes the oxidation of fatty aldehyde to fatty acid. More than 70 mutations have been identified in SLS patients, including small deletions or insertions, missense mutations, splicing defects and complex nucleotide changes. We now describe 2 SLS patients whose disease is caused by large contiguous gene deletions of the ALDH3A2 locus on 17p11.2. The deletions were defined using long distance inverse PCR and microarray-based comparative genomic hybridization. A 24-year-old SLS female was homozygous for a 352-kb deletion involving ALDH3A2 and 4 contiguous genes including ALDH3A1, which codes for the major soluble protein in cornea. Although lacking corneal disease, she showed severe symptoms of SLS with uncommon deterioration in oral motor function and loss of ambulation. The other 19-month-old female patient was a compound heterozygote for a 1.44-Mb contiguous gene deletion and a missense mutation (c.407C>T, P136L) in ALDH3A2. These studies suggest that large gene deletions may account for up to 5% of the mutant alleles in SLS. Geneticists should consider the possibility of compound heterozygosity for large deletions in patients with SLS and other inborn errors of metabolism, which has implications for carrier testing and prenatal diagnosis.
Molecular Genetics and Metabolism 05/2011; 104(3):356-61. · 3.19 Impact Factor
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ABSTRACT: Krabbe disease is an infantile-onset progressive leukodystrophy. The classic presentation includes excessive irritability, muscle hypertonicity, developmental delay, failure to thrive, peripheral neuropathy, seizures, and optic nerve atrophy. The authors report a rare case of optic nerve enlargement early in infantile Krabbe disease. Their case demonstrates proximal prechiasmatic enlargement of the nerves. They discuss the pathophysiological and clinical correlation of optic nerve enlargement in Krabbe disease and in other disorders. Although Krabbe disease does not feature in initial differential of optic nerve enlargement in children, its inclusion and early identification facilitate a timely diagnosis of this rapidly progressive fatal disease.
Journal of child neurology 01/2011; 26(5):642-4. · 1.59 Impact Factor
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ABSTRACT: Human FOXP2 deficiency has been identified as a cause of hereditary developmental verbal dyspraxia. Another member of the same gene family, FOXP1, has expression patterns that overlap with FOXP2 in some areas of the brain, and FOXP1 and FOXP2 have the ability to form heterodimers. These findings suggest the possibility that FOXP1 may also contribute to proper speech development. However, no such role of FOXP1 has been established to date. Recently, a child was reported who presented with a 3p13-14.1 deletion of four genes, including FOXP1, and a constellation of deficits that included speech delay. In this study, we report the case of a patient with a single deletion of FOXP1. This patient presented with speech and motor developmental delays, a Chiari I malformation, and epileptiform discharges. The nature of the speech deficit is different from the primary oromotor verbal dyspraxia found in patients with FOXP2 deficiency. The patient's developmental deficits may support a role for FOXP1 in the development of verbal and motor skills.
European journal of human genetics: EJHG 11/2010; 18(11):1216-20. · 3.56 Impact Factor
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ABSTRACT: X-linked creatine transporter defect is caused by mutations in SLC6A8 at Xq28, which encodes the sodium-dependent creatine transporter. Reduction in creatine uptake results in elevated urine creatine and CSF creatine deficiency, which can be detected on magnetic resonance spectroscopy. We report a patient who was initially suspected of having a mitochondrial disorder but was later found to have a creatine transporter defect. The abnormal laboratory study results seen in this patient suggesting a mitochondrial cytopathy could be due to excess mitochondrial stress as well as the mitochondrial inclusion bodies. This report looks at the mitochondrial presentation of the creatine transporter deficiency.
Journal of child neurology 08/2010; 25(8):1009-12. · 1.59 Impact Factor
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Sérgio B Sousa, Omar A Abdul-Rahman,
Armand Bottani,
Valérie Cormier-Daire,
Alan Fryer,
Gabriele Gillessen-Kaesbach,
Denise Horn,
Dragana Josifova,
Alma Kuechler,
Melissa Lees, [......],
Alex Magee,
Fanny Morice-Picard,
Elizabeth Rosser,
Ajoy Sarkar,
Nora Shannon,
Irene Stolte-Dijkstra,
Alain Verloes,
Emma Wakeling,
Louise Wilson,
Raoul C M Hennekam
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ABSTRACT: Nicolaides-Baraitser syndrome (NBS) is an infrequently described condition, thus far reported in five cases. In order to delineate the phenotype and its natural history in more detail, we gathered data on 18 hitherto unreported patients through a multi-center collaborative study, and follow-up data of the earlier reported patients. A detailed comparison of the 23 patients is provided. NBS is a distinct and recognizable entity, and probably has been underdiagnosed until now. Main clinical features are severe mental retardation with absent or limited speech, seizures, short stature, sparse hair, typical facial characteristics, brachydactyly, prominent finger joints and broad distal phalanges. Some of the features are progressive with time. The main differential diagnosis is Coffin-Siris syndrome. There is no important gender difference in occurrence and frequency of the syndrome, and all cases have been sporadic thus far. Microarray analysis performed in 14 of the patients gave normal results. Except for the progressive nature there are no clues to the cause.
American Journal of Medical Genetics Part A 09/2009; 149A(8):1628-40. · 2.39 Impact Factor
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ABSTRACT: Hypoplastic glomerulocystic kidney disease is an autosomal dominant disorder caused by mutations in hepatocyte nuclear factor-1beta. Hepatoblastoma is a sporadic occurring tumor of embryonal origin that has been associated with the several overgrowth syndromes. We report a case of concomitant hypoplastic glomerulocystic kidney disease and hepatoblastoma. Review of the literature identified 4 other patients with a similar association. We propose that hypoplastic glomerulocystic kidney disease and hepatoblastoma represent a possible association, and we excluded mutations in hepatocyte nuclear factor-1beta in our patient as causative of this putative association.
Journal of Pediatric Hematology/Oncology 08/2009; 31(7):527-9. · 1.16 Impact Factor
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ABSTRACT: In 1992, van den Ende et al. first reported an autosomal recessive multiple congenital anomaly syndrome characterized by blepharophimosis, arachnodactyly, and congenital contractures in a Brazilian girl born to consanguineous parents. Since then, nine total patients have been reported with van den Ende-Gupta syndrome (VDEGS), and the syndrome's phenotype has been found to also include additional dysmorphic facial features, palatal abnormalities, and slender skeletal features. We present two African-American sisters born to nonconsanguineous parents who have been diagnosed with VDEGS. Both sisters developed stridor and were found to have an unusual malformation characterized by large, globular cuneiform cartilages, shortened aryepiglottic folds, a tightly coiled epiglottis, and laryngomalacia. Both patients underwent supraglottoplasty with a successful outcome. A review of the literature reveals that airway problems have been reported in a previous patient. However, no specific airway anomaly has been reported. We suggest that all patients with VDEGS and stridor undergo direct laryngoscopy with consideration for surgical correction.
American Journal of Medical Genetics Part A 12/2007; 143A(22):2706-11. · 2.39 Impact Factor
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Silke Schlaubitz,
Svetlana A Yatsenko,
Laurie D Smith,
Kory L Keller,
Lisenka E Vissers,
Daryl A Scott,
Wei Wen Cai,
William Reardon, Omar A Abdul-Rahman,
Edward J Lammer,
Caroline A Lifchez,
Ellen Magenis,
Joris A Veltman,
Pawel Stankiewicz,
Bernhard U Zabel,
Brendan Lee
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ABSTRACT: We describe our findings in a 46,XY female with a clinical features of Genitopatellar syndrome (GPS) and confirmed hermaphroditism with ovotestes, and five additional patients with GPS. GPS is a genetic disorder characterized by renal and genital anomalies, joint dislocation, aplastic or hypoplastic and often displaced patellae, minor facial anomalies, and mental retardation. The genital anomalies clearly distinguish GPS from nail-patella syndrome (NPS) that has similar features, but additionally shows hypoplastic finger- and toenails as found in the 46,XY female. In our patients no mutation was found in the coding regions of WNT4, WNT7A, TBX4, and LMX1B. Fluorescent in situ hybridization (FISH) and array-based comparative genome hybridization (aCGH) analysis showed a 3 Mb deletion of LMX1B, NR6A1, and NR5A1 (SF1) in the 46,XY female. This is the first report of a microdeletion causing haploinsuffiency of LMX1B and NR5A1. The deletion of LMX1B is responsible for the knee anomalies and the deletion of NR5A1 likely causes the sex reversal. Cytogenetic analysis of the five additional patients with diagnosed GPS failed to identify a similar microdeletion, or inversion of a potentially regulatory element between the two genes. This suggests that the locus 9q33-9q34 can be excluded for GPS and that the presented case is unique in its combination of GPS and NPS features caused by a microdeletion associated with loss of function of LMX1B and NR5A1.
American Journal of Medical Genetics Part A 06/2007; 143A(10):1071-81. · 2.39 Impact Factor
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ABSTRACT: Genitopatellar syndrome is a newly described disorder characterized by absent/hypoplastic patellae, lower extremity contractures, urogenital anomalies, dysmorphic features, skeletal anomalies, and agenesis of the corpus callosum. More recently, cardiac anomalies and ectodermal dysplasia have been suggested as additional features of this syndrome. We report on two additional patients with genitopatellar syndrome and expand the spectrum of anomalies to include radio-ulnar synostosis. Since there exists significant overlap in the skeletal phenotype between genitopatellar syndrome and both the nail-patella and short patella syndromes, mutation screening of their causative genes, LMX1B and TBX4, was performed. Although there still does not appear to be an identifiable molecular etiology in genitopatellar syndrome, mutations in these two candidate genes have been excluded in our patients. Since both LMX1B and TBX4 are involved in a common molecular pathway, it is likely that the causative gene of genitopatellar syndrome functions within the same developmental process.
American Journal of Medical Genetics Part A 08/2006; 140(14):1567-72. · 2.39 Impact Factor
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ABSTRACT: A genetics evaluation of children with pervasive developmental disorders (PDDs) identifies a diagnosis in 6% to 15% of cases. However, previous studies have not measured the incidence of genetic disorders among children with autistic-like features who do not necessarily meet the Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition criteria for PDD.
We identified 101 patients at our institution referred for PDD, autism, Asperger syndrome, or autistic features. Seventy-eight were males and 23 were females, giving a male-to-female ratio of 3.4:1. No diagnosis was identified on examination alone, although Rett syndrome was suspected in six females. Seventeen patients did not undergo any type of testing because of noncompliance.
Of the remaining 84 patients analyzed, seven (8.3%) were found to have abnormalities on testing. Three chromosomal anomalies were found: one with 5p duplication, one with low-level mosaicism for trisomy 21, and one with an unbalanced 10;22 translocation. Three females were diagnosed with Rett syndrome after MECP2 analysis identified a disease-causing mutation. The remaining patient was found to have an elevated urine orotic acid, with a normal ammonia level, of unknown significance.
On the basis of our series, the yield of a genetics evaluation in patients with features of PDD who do not necessarily meet the Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition criteria is 8.3%. Approximately half of these were the result of a chromosomal abnormality. Three cases of Rett syndrome were identified for which autistic behaviors are a well-described feature. These findings suggest that a high-resolution karyotype provides the greatest diagnostic yield for patients with autistic-like features. MECP2 analysis should be considered for females who present with autistic behaviors.
Genetics in Medicine 02/2006; 8(1):50-4. · 4.76 Impact Factor
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ABSTRACT: Disseminated cryptococcal disease is often associated with immunodeficient states. The diagnosis is usually made using standard antigen tests on serum and cerebrospinal fluid in patients with known immunodeficiency. Often, blood and cerebrospinal fluid cultures also yield Cryptococcus neoformans. The authors describe a child whose diagnosis remained elusive until a bone marrow aspiration, performed as part of an evaluation for suspected neoplasm, revealed the offending organism.
Journal of Pediatric Hematology/Oncology 09/2004; 26(8):526-8. · 1.16 Impact Factor
