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Background Borjeson–Forssman–Lehmann syndrome (BFLS) is an X-linked recessive intellectual disability (ID) disorder caused by mutations in the PHF6 gene and characterised by variable cognitive impairment, a distinct facial gestalt, obesity, and hypogonadism. Female carriers are usually not affected or only mildly affected, and so far only two females with de novo mutations or deletions in PHF6 have been reported. Methods and results We performed PHF6 mutational analysis and screening for intragenic deletions and duplications by quantitative real-time PCR and multiplex ligation dependent probe amplification (MLPA) in female patients with variable ID and a distinct appearance of sparse hair, remarkable facial features, hypoplastic nails, and teeth anomalies. We detected two truncating mutations and two duplications of exons 4 and 5. Furthermore, two female patients with PHF6 deletions and a similar phenotype were identified by routine molecular karyotyping. Recently, two patients with a clinical diagnosis of Coffin-Siris syndrome in early infancy had been found to harbour mutations in PHF6 , and their phenotype in advanced ages is now described. Further studies revealed skewed X-inactivation in blood lymphocytes, while it was normal in fibroblasts, thus indicating functional mosaicism. Conclusions Our findings indicate that de novo defects in PHF6 in females result in a recognisable phenotype which might have been under-recognised so far and which comprises variable ID, a characteristic facial gestalt, hypoplastic nails, brachydactyly, clinodactyly mainly of fingers IV and V, dental anomalies, and linear skin hyperpigmentation. It shows overlap with BFLS but also additional distinct features, thus adding a new facet to this disorder.

We report a sibship in which the syndrome of congenital arthrogryposis occurred in two male and two female neonates, three of whom died. The mother was asymptomatic at the time of the first pregnancy and the subsequent development of muscle weakness was later confirmed to be due to myasthenia gravis. The literature on this association is briefly reviewed and the extremely high risk of recurrence of this complication in subsequent pregnancies is addressed.

We report six sibs with arthrogryposis multiplex congenita and a Pena-Shokeir phenotype, born to a healthy woman who was discovered to have asymptomatic myasthenia gravis (MG). This is the first report of anti-acetylcholine receptor (AChR) antibodies causing fetal akinesia/hypokinesia sequence in the offspring of an asymptomatic mother. Am. J. Med. Genet. 92:1–6, 2000. © 2000 Wiley-Liss, Inc.

Pelizaeus-Merzbacher-like disease (PMLD) is a clinically and genetically heterogeneous neurological disorder of cerebral hypomyelination. It is clinically characterised by early onset (usually infantile) nystagmus, impaired motor development, ataxia, choreoathetoid movements, dysarthria and progressive limb spasticity. We undertook autozygosity mapping studies in a large consanguineous family of Pakistani origin in which affected children had progressive lower limb spasticity and features of cerebral hypomyelination on MR brain imaging. SNP microarray and microsatellite marker analysis demonstrated linkage to chromosome 1q42.13 -> 1q42.2. Direct sequencing of the gap junction protein gamma-2 gene. GJC2, identified a promoter region mutation (c.-167A>G) in the non-coding exon 1. The c.-167A>G promoter mutation was identified in a further 4 individuals from two families (who were also of Pakistani origin) with clinical and radiological features of PMLD in whom previous routine diagnostic screening of GJC2 had been reported as negative. A common haplotype was identified at the GJC2 locus in the three mutation-positive families, consistent with a common origin for the mutation and likely founder effect. This promoter mutation has only recently been reported in GJC2-PMLD but it has been postulated to affect the binding of the transcription factor SOX10 and appears to be a prevalent mutation, accounting for similar to 29% of reported patients with GJC2-PMLD. We propose that diagnostic screening of GJC2 should include sequence analysis of the non-coding exon 1, as well as the coding regions to avoid misdiagnosis or diagnostic delay in suspected PMLD. (C) 2011 Elsevier Inc. All rights reserved

Background/Aims: Mutations in the inwardly-rectifying K+ channel KCNJ10/Kir4.1 cause an autosomal recessive disorder characterized by epilepsy, ataxia, sensorineural deafness and tubulopathy (EAST syndrome). KCNJ10 is expressed in the kidney distal convoluted tubule, cochlear stria vascularis and brain glial cells. Patients clinically diagnosed with EAST syndrome were genotyped to identify and study mutations in KCNJ10. Methods: Patient DNA was sequenced and new mutations identified. Mutant and wild-type KCNJ10 constructs were cloned and heterologously expressed in Xenopus oocytes. Whole-cell K+ currents were measured by two-electrode voltage clamping. Results: Three new mutations in KCNJ10 (p.R65C, p.F75L and p.V259fs259X) were identified, and mutation p.R297C, previously only seen in a compound heterozygous patient, was found in a homozygous state. Wild-type human KCNJ10-expressing oocytes showed strongly inwardly-rectified currents, which by comparison were significantly reduced in all the mutants (p < 0.001). Specific inhibition of KCNJ10 currents by Ba2+ demonstrated residual function in all mutant channels (p < 0.05) but V259X. Conclusion: This study confirms that EAST syndrome can be caused by many different mutations in KCNJ10 that significantly reduce K+ conductance. EAST syndrome should be considered in any patient with a renal Gitelman-like phenotype with additional neurological signs and symptoms like ataxia, epilepsy or sensorineural deafness.

ARX mutations cause a diverse spectrum of human disorders, ranging from severe brain and genital malformations to non-syndromic intellectual disability (ID). ARX is a transcription factor with multiple domains that include four polyalanine (pA) tracts, the first two of which are frequently expanded by mutations. We progressively screened DNA samples from 613 individuals with ID initially for the most frequent ARX mutations (c.304ins(GCG)(7)'expansion' of pA1 and c.429_452dup 'dup24bp' of pA2). Five hundred samples without pA1 or pA2 mutations had the entire ARX ORF screened by single stranded polymorphism conformation (SSCP) and/or denaturing high pressure liquid chromatography (dHPLC) analysis. Overall, eight families with six mutations in ARX were identified (1.31%): five duplication mutations in pA2 (0.82%) with three new clinical reports of families with the dup24bp and two duplications larger than the dup24bp mutation discovered (dup27bp, dup33bp); and three point mutations (0.6%), including one novel mutation in the homeodomain (c.1074G>T). Four ultraconserved regions distal to ARX (uc466-469) were also screened in a subset of 94 patients, with three unique nucleotide changes identified in two (uc466, uc467). The subcellular localization of full length ARX proteins was assessed for 11 variants. Protein mislocalization increased as a function of pA2 tract length and phenotypic severity, as has been previously suggested for pA1. Similarly, protein mislocalization of the homeodomain mutations also correlated with clinical severity, suggesting an emerging genotype vs cellular phenotype correlation.

Contains fulltext : 80644.pdf (Publisher’s version ) (Closed access) Interstitial deletions of 7q11.23 cause Williams-Beuren syndrome, one of the best characterized microdeletion syndromes. The clinical phenotype associated with the reciprocal duplication however is not well defined, though speech delay is often mentioned. We present 14 new 7q11.23 patients with the reciprocal duplication of the Williams-Beuren syndrome critical region, nine familial and five de novo. These were identified by either array-based MLPA or by array-CGH/oligonucleotide analysis in a series of patients with idiopathic mental retardation with an estimated population frequency of 1:13,000-1:20,000. Variable speech delay is a constant finding in our patient group, confirming previous reports. Cognitive abilities range from normal to moderate mental retardation. The association with autism is present in five patients and in one father who also carries the duplication. There is an increased incidence of hypotonia and congenital anomalies: heart defects (PDA), diaphragmatic hernia, cryptorchidism and non-specific brain abnormalities on MRI. Specific dysmorphic features were noted in our patients, including a short philtrum, thin lips and straight eyebrows. Our patient collection demonstrates that the 7q11.23 microduplication not only causes language delay, but is also associated with congenital anomalies and a recognizable face.

BACKGROUND: Beckwith-Wiedemann syndrome (BWS) is a model imprinting disorder resulting from mutations or epigenetic events affecting imprinted genes at I I pI5.5. Most BWS cases are sporadic and result from imprinting errors (epimutations) involving either of the two I I p 15.5 imprinting control regions (IC I and IC2). Previously, we and other reported an association between sporadic BWS and assisted reproductive technologies (ARTs). METHODS: In this study, we compared the clinical phenotype and molecular features of ART (IVF and ICSI) and non-ART children with sporadic BWS. A total of 25 patients with post-ART BWS were ascertained (12 after IVF and 13 after ICSI). RESULTS: Molecular genetic analysis revealed an IC2 epimutations (KvDMRI loss of methylation) in 24 of the 25 children tested. Comparison of clinical features of children with post-ART BWS to those with non-ART BWS and IC2 defects revealed a lower frequency of exomphalos (43 versus 69%, P= 0.029) and a higher risk of neoplasia (two cases, P= 0.0014). As loss of methylation at imprinting control regions other than I I p 15.5 might modify the phenotype of BWS patients with IC2 epimutations, we investigated differentially methylated regions (DMRs) at 6q24, 7q32 and I5qI3 in post-ART and non-ART BWS IC2 cases (n = 55). Loss of maternal allele methylation at these DMRs occurred in 37.5% of ART and 6.4% of non-ART BWS IC2 defect cases. Thus, more generalized DMR hypomethylation is more frequent, but not exclusive to post-ART BWS. CONCLUSIONS: These findings provide further evidence that ART may be associated with disturbed normal genomic imprinting in a subset of children.

Increasing use of fertility therapy has elicited concerns regarding adverse effects for expectant mothers and the health of children thus conceived.To study the risk of adverse perinatal outcomes, birth defects and pregnancy complications following assisted reproductive technology (ART).Questionnaire-based study involving 1,524 children and 1,182 pregnancies conceived following in vitro fertilisation (IVF) in two units. Outcomes were compared with the general population.In the study group versus the general population; multi-foetal gestations, 26 versus 2%; singleton preterm delivery and low birth weight, 8.7 and 6.4 versus 4.3 and 4%, respectively; non-lethal congenital malformation rate, 2.6 versus 2.1%; placenta praevia, 2.8 versus 0.5%.Multi-foetal gestations remain the principal cause of adverse perinatal outcomes after ART. Singleton ART pregnancies have an increased risk of preterm delivery and low birth weight at term. Non-lethal congenital malformation rates are not increased following ART. Placenta praevia is increased following ART.

Copy number variations are a common cause of intellectual disability (ID). Determining the contribution of copy number variants (CNVs), particularly gains, to disease remains challenging. Here, we report four males with ID with sub-microscopic duplications at Xp11.2 and review the few cases with overlapping duplications reported to date. We established the extent of the duplicated regions in each case encompassing a minimum of three known disease genes TSPYL2, KDM5C and IQSEC2 with one case also duplicating the known disease gene HUWE1. Patients with a duplication encompassing TSPYL2, KDM5C and IQSEC2 without gains of nearby SMC1A and HUWE1 genes have not been reported thus far. All cases presented with ID and significant deficits of speech development. Some patients also manifested behavioral disturbances such as hyperactivity and attention-deficit/hyperactivity disorder. Lymphoblastic cell lines from patients show markedly elevated levels of TSPYL2, KDM5C and SMC1A, transcripts consistent with the extent of their CNVs. The duplicated region in our patients contains several genes known to escape X-inactivation, including KDM5C, IQSEC2 and SMC1A. In silico analysis of expression data in selected gene expression omnibus series indicates that dosage of these genes, especially IQSEC2, is similar in males and females despite the fact they escape from X-inactivation in females. Taken together, the data suggest that gains in Xp11.22 including IQSEC2 cause ID and are associated with hyperactivity and attention-deficit/hyperactivity disorder, and are likely to be dosage-sensitive in males.

BACKGROUND: Genomic imprinting is an epigenetic process in which allele-specific gene expression is dependent on the parental inheritance. Although only a minority of human genes are imprinted, those that have been identified to date have been preferentially implicated in prenatal growth and neurodevelopment. Mutations or epimutations in imprinted genes or imprinting control centres are associated with imprinting disorders such as Angelman syndrome (AS) and Beckwith‐Wiedemann syndrome (BWS). Recently, an increased frequency of assisted reproductive technology (ART) conceptions has been reported in children with BWS and AS. However, the risk of imprinting disorders in ART children is unknown. METHODS: We undertook a survey of 2492 children born after ART in the Republic of Ireland and Central England with the aim of detecting cases (both clinically diagnosed and previously unrecognized) of BWS and AS in this cohort. The response rate to an initial questionnaire was 61%, corresponding to data for 1524 children. After evaluation of the questionnaire, 70 children were invited for a detailed clinical assessment, and 47 accepted (response rate of 67%). RESULTS: In this entire cohort, we detected one case of BWS and no cases of AS. We did not find evidence that there exists a significant group of ART children with unrecognized milder forms of AS or BWS. CONCLUSIONS: Although previous studies have suggested an increased relative risk of BWS and AS after ART, our findings suggest that the absolute risk of imprinting disorders in children conceived by ART is small (

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:22:37Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:33:38Z : No. of bitstreams: 1 2-s2.0-35349019691.pdf: 4144234 bytes, checksum: 9b86846640bd2e66375c65e289357bd0 (MD5) Made available in DSpace on 2014-05-27T11:22:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-10-24 Aicardi-Goutières syndrome (AGS) is a genetic encephalopathy whose clinical features mimic those of acquired in utero viral infection. AGS exhibits locus heterogeneity, with mutations identified in genes encoding the 3′→5′ exonuclease TREX1 and the three subunits of the RNASEH2 endonuclease complex. To define the molecular spectrum of AGS, we performed mutation screening in patients, from 127 pedigrees, with a clinical diagnosis of the disease. Biallelic mutations in TREX1, RNASEH2A, RNASEH2B, and RNASEH2C were observed in 31, 3, 47, and 18 families, respectively. In five families, we identified an RNASEH2A or RNASEH2B mutation on one allele only. In one child, the disease occurred because of a de novo heterozygous TREX1 mutation. In 22 families, no mutations were found. Null mutations were common in TREX1, although a specific missense mutation was observed frequently in patients from northern Europe. Almost all mutations in RNASEH2A, RNASEH2B, and RNASEH2C were missense. We identified an RNASEH2C founder mutation in 13 Pakistani families. We also collected clinical data from 123 mutation-positive patients. Two clinical presentations could be delineated: an early-onset neonatal form, highly reminiscent of congenital infection seen particularly with TREX1 mutations, and a later-onset presentation, sometimes occurring after several months of normal development and occasionally associated with remarkably preserved neurological function, most frequently due to RNASEH2B mutations. Mortality was correlated with genotype; 34.3% of patients with TREX1, RNASEH2A, and RNASEH2C mutations versus 8.0% RNASEH2B mutation-positive patients were known to have died (P = .001). Our analysis defines the phenotypic spectrum of AGS and suggests a coherent mutation-screening strategy in this heterogeneous disorder. Additionally, our data indicate that at least one further AGS-causing gene remains to be identified. © 2007 by The American Society of Human Genetics. All rights reserved. Leeds Institute of Molecular Medicine, Leeds DNA Laboratory Department of Clinical Genetics St. James's University Hospital, Leeds Cancer Research UK Mutation Detection Facility, Leeds Department of Paediatric Neurology Leeds General Infirmary, Leeds Department of Paediatric Neurology Erasme Hospital, Brussels Children's Hospital Queen Fabiola, Brussels Service de Neuropédiatrie Hôpital Trousseau Department of Paediatric Neurology Hôpital Trousseau Pediatric Neurology Department Hôpital Bicêtre Institut de Myologie Groupe Hospitalier Pitié-Salpêtrière Service de Virologie Hôpital Cochin-St. Vincent de Paul, Paris Department of Clinical Biochemistry Hospital Sant Joan de Déu-Ciberer, Barcelona Department of Barcelona Pediatric Neurology Hospital Sant Joan de Déu-Ciberer, Barcelona Department of Paediatrics St. Luke's Hospital, Guardamangia Department of Molecular and Human Genetics Baylor College of Medicine, Houston Serive de Neurologie Centre Hospitalier, Pau Department of Paediatrics Children's Hospital, Sheffield Developmental and Metabolic Neurology Branch National Institute of Neurological Disorders and Stroke National Institutes of Health, Bethesda Department of Human Genetics Rheinisch-Westfälische Technische Hochschule Aachen University, Aachen Unit of Molecular Medicine Bambino Gesù Children's Research Hospital, Rome Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Casa Sollievo Della Sofferenza Mendel Institute, Rome Muscular and Neurodegenerative Disease Unit G. Gaslini Institute, Genova Department of Clinical Genetics Churchill Hospital, Oxford Division of Clinical Chemistry and Biochemistry University Children's Hospital, Zurich Clinical Genetics Unit Birmingham Women's Hospital, Birmingham Department of Paediatrics Sandwell and West Birmingham NHS Trust, Birmingham Neurology Department Birmingham Children's Hospital, Birmingham Department of Human Genetics Radboud University, Nijmegen Department of Pediatric Neurology Radboud University, Nijmegen Department of Paediatric Neurology Royal Children's Hospital, Brisbane, QLD Genetic Health Queensland Royal Children's Hospital, Brisbane, QLD Serviço de Aconselhamento Genético Universidade Estadual de São Paulo, Botucatu Academic Unit of Medical Genetics St. Mary's Hospital, Manchester Kinderkrankenhaus Auf der Bult, Hannover Department of Paediatrics Bradford National Health Service (NHS) Trust, Bradford Developmental Neurology Department Fondazione Istituto Neurologico C. Besta, Milan Grampian Clinical Genetics Centre, Aberdeen Department of Neonatology University Hospital, Ghent Department of Pediatrics University Hospital, Ghent Department of Clinical Genetics Maastricht University Hospital, Maastricht Department of Neurology Maastricht University Hospital, Maastricht Department of Paediatrics and Imaging Sciences Imperial College Great Ormond Street Hospital, London St. Mary's NHS Trust Great Ormond Street Hospital, London Department of Ophthalmology Great Ormond Street Hospital, London North East Thames Regional Genetics Service Great Ormond Street Hospital, London Evelina Children's Hospital Guy's and St. Thomas' NHS Trust, London Department of Paediatrics Université Laval Medical School, Québec Clinical Genetics Unit Hospital de Cruces, Baracaldo Service de Génétique Médicale Centre Hospitalier Universitaire Pellegrin Enfants, Bordeaux Unité de Neurologie de l'Enfant et de l'Adolescent Centre Hospitalier Universitaire Pellegrin Enfants, Bordeaux National Centre for Medical Genetics Our Lady's Hospital, Dublin Department of Paediatric Neurology Children's University Hospital, Dublin Department of Medical Genetics Rikshospitalet-Radiumhospitalet, Oslo Department of Paediatrics Rikshospitalet-Radiumhospitalet, Oslo Rikshospitalet-Radiumhospitalet, Oslo Department of Pediatrics Academic Medical Center, Amsterdam Department of Child Neurology Vrije Universiteit Medical Center, Amsterdam Medical Research Council Human Genetics Unit Western General Hospital, Edinburgh Department of Clinical Genetics Leiden University Medical Center, Leiden Division of Pediatric Neurology Oregon Health and Science University, Portland, OR Pediatric Neurology Klinikum Aschaffenburg, Aschaffenburg Department of Neurology Royal Children's Hospital, Parkville, Vic. Division of Clinical Genetics Department for Medical Genetics Medical University Innsbruck, Innsbruck Department of Pediatrics Division of Pediatric Neurology and Inborn Errors of Metabolism Children's Hospital Innsbruck, Innsbruck Klinik für Kinder und Jugendliche, Konstanz Paediatric Neurology University Hospitals of Gasthuisberg, Leuven Department of Child Neurology and Psychiatry IRCCS Casimiro Mondino Institute of Neurology, Pavia Department of Neurogenetics School of Medicine of Ribeirao Preto, Ribeirao Preto Greenwood Genetic Center, Greenwood, SC Raphael Recanati Genetic Institute Rabin Medical Center, Petach-Tikva Department of Paediatrics Crosshouse Hospital, Ayr Fraser of Allander Neurosciences Unit Royal Hospital for Sick Children, Glasgow Duncan Guthrie Institute of Medical Genetics Royal Hospital for Sick Children, Glasgow Division of Medical Genetics Montreal Children's Hospital, Montreal Department of Paediatric Neurology University Hospitals of Leicester NHS Trust, Leicester University Hospital of Aarhus, Aarhus Division of Pediatric Dermatology British Columbia's Children's Hospital, Vancouver, BC Institut de Pathologie et de Génétique, Gosselies Pediatric Neurology Department Guide Chauliac Hospital, Montpellier Servicio de Pediatría Hospital Universitario Doctor Peset, Valencia Genetic Institute Ha'Emek Medical Center, Afula Rappaport Faculty of Medicine Technion, Haifa Neuropediatrics Unit Complejo Hospitalario de Jean, Jean Department of Paediatrics Manor Hospital, Walsall Division of Neuropediatrics University Hospital, Freiburg Genetic Health Services Victoria Royal Children's Hospital, Vic. Service de Génétique Hôpital Debrousse, Lyon Lancashire Teaching Hospitals Trust, Preston Neonatal Intensive Care Unit Arcispedale Santa Maria Nuova, Reggio Emilia Center for Medical Genetics, Antwerp Department of Neurology Children's National Medical Center, Washington, DC Department of Neuropediatrics Humboldt University, Berlin Leeds Institute of Molecular Medicine St. James's University Hospital Wellcome Trust Brenner Building, Leeds LS9 7TF Serviço de Aconselhamento Genético Universidade Estadual de São Paulo, Botucatu

We report on the first case of fumarase deficiency (FD) caused by uniparental isodisomy. An affected patient was found to be homozygous for the P131R mutation in the FH gene. In this nonconsanguineous family, the unaffected father was found to be heterozygous for the same mutation, and the mother was found to be homozygous wild-type. Analysis of chromosome 1 markers showed that the patient inherited both paternal alleles with complete absence of the maternal homolog. The two copies of the paternal chromosome 1 are heterodisomic for most of the chromosome except the distal 1q region which is isodisomic for the mutant alleles of the FH gene. The genotypes of other chromosome markers are consistent with the patient inheriting alleles from both parents. Although FD is an autosomal recessive disorder, the effects of uniparental disomy (UPD) should be considered in genetic counseling since the recurrence risk of an affected child is significantly reduced when the disorder is due to UPD.

Terminal deletions of the long arm of chromosome 2 (2q37) have been recorded in the literature for more than a decade and an associated syndrome first became apparent when nine patients were reported with an Albright hereditary osteodystrophy (AHO)-like metacarpal/metatarsal shortening (brachymetaphalangism).1,2 This is also known as brachydactyly-mental retardation syndrome (BDMR, MIM 600430). To date, some 60 or so cases of 2q37 deletion or monosomy resulting from unbalanced translocations have been reported. Significant variability in clinical presentation is apparent, but almost all patients have some degree of mental retardation and facial dysmorphism. Brachymetaphalangism has been reported in approximately 50% of cases.1–15 Congenital heart anomalies are present in around 20% of patients with 2q37 monosomy,16–22 compared to 1% of the general population. These are predominantly atrial or ventricular septal defects, but more complex problems have been reported.17,22 Additionally, there are two reports of tetralogy of Fallot with monosomy 2q37 resulting from unbalanced translocations,23,24 but both cases were also trisomic for 17q25 and it is not clear which imbalance was causative. Other phenotypes repeatedly associated with 2q37 deletions include Wilms tumor and urogenital anomalies,6,17,19 epilepsy,1,2,7–9,14,16,20,25–27 eczema,2,5–7,16,28,29 and autism or repetitive, hyperkinetic behaviour.1,2,5,7,10,11,15,16,19,25,26,28–32 Situs abnormalities have been reported in two cases9 and holoprosencephaly in one infant.33 Most 2q37 rearrangements reported to date have been only minimally characterised by conventional cytogenetics or subtelomeric fluorescent in situ hybridisation (FISH). A small number have been subjected to more detailed analysis using multiple FISH clones or microsatellite markers,2,10,15,26 but the ability to assign breakpoints and make genotype–phenotype correlations has been …

ShprintzenGoldberg syndrome (SGS) is a rare, systemic connective tissue disorder characterized by craniofacial, skeletal, and cardiovascular manifestations that show a significant overlap with the features observed in the Marfan (MFS) and LoeysDietz syndrome (LDS). A distinguishing observation in SGS patients is the presence of intellectual disability, although not all patients in this series present this finding. Recently, SGS was shown to be due to mutations in the SKI gene, encoding the oncoprotein SKI, a repressor of TGFβ activity. Here, we report eight recurrent and three novel SKI mutations in eleven SGS patients. All were heterozygous missense mutations located in the R-SMAD binding domain, except for one novel in-frame deletion affecting the DHD domain. Adding our new findings to the existing data clearly reveals a mutational hotspot, with 73% (24 out of 33) of the hitherto described unrelated patients having mutations in a stretch of five SKI residues (from p.(Ser31) to p.(Pro35)). This implicates that the initial molecular testing could be focused on mutation analysis of the first half of exon 1 of SKI. As the majority of the known mutations are located in the R-SMAD binding domain of SKI, our study further emphasizes the importance of TGFβ signaling in the pathogenesis of SGS.

Albright hereditary osteodystrophy (AHO) results from heterozygous inactivation of Gsα, encoded by the GNAS1 locus on the distal long arm of chromosome 20. This autosomal dominant condition is characterized by short stature, obesity, shortening of the metacarpals and metatarsals, and variable mental retardation and may also include end-organ resistance to multiple hormones. Small insertions and deletions or point mutations of GNAS1 are found in approximately 80% of patients with AHO. The remainder may be accounted for by larger genomic rearrangements, but none have been reported to date. We now describe two patients with constitutional 20q deletions and features of AHO. Such deletions are rare in the published literature and have not previously been associated with AHO. Molecular genetic analysis confirmed complete deletion of GNAS1 in both patients. Parental origin could be determined in both cases and provides further support for the parent-of-origin effect on the biochemical status of patients with AHO. © 2002 Wiley-Liss, Inc.

SummaryCleidocranial dysplasia (CCD) is a dominantly inherited disorder characterized by patent fontanelles, wide cranial sutures, hypoplasia of clavicles, short stature, supernumerary teeth, and other skeletal anomalies. We recently demonstrated that mutations in the transcription factor CBFA1, on chromosome 6p21, are associated with CCD. We have now analyzed the CBFA1 gene in 42 unrelated patients with CCD. In 18 patients, mutations were detected in the coding region of the CBFA1 gene, including 8 frameshift, 2 nonsense, and 9 missense mutations, as well as 2 novel polymorphisms. A cluster of missense mutations at arginine 225 (R225) identifies this residue as crucial for CBFA1 function. In vitro green fluorescent protein fusion studies show that R225 mutations interfere with nuclear accumulation of CBFA1 protein. There is no phenotypic difference between patients with deletions or frameshifts and those with other intragenic mutations, suggesting that CCD is generally caused by haploinsufficiency. However, we were able to extend the CCD phenotypic spectrum. A missense mutation identified in one family with supernumerary teeth and a radiologically normal skeleton indicates that mutations in CBFA1 can be associated exclusively with a dental phenotype. In addition, one patient with severe CCD and a frameshift mutation in codon 402 had osteoporosis leading to recurrent bone fractures and scoliosis, providing first evidence that CBFA1 may help maintain adult bone, in addition to its function in bone development.

We report on 3 consecutive sib fetuses, presenting at 13, 12, and 13 weeks of gestation, respectively, with fetal hydrops, limb contractures, and akinesia. Autopsy of the first fetus showed subcutaneous fluid collections and severe degeneration of skeletal muscle. Histologic studies demonstrated massive accumulation of diastase-resistant periodic acid-Schiff-positive material in the skeletal muscle cells and epidermal keratinocytes of all 3 fetuses. Enzyme studies of fibroblasts from the 3rd fetus showed deficient activity of glycogen brancher enzyme, indicating that this is a new, severe form of glycogenosis type IV with onset in the early second trimester.

We present a dizygotic twin pair each with ventriculomegaly, a radial ray defect and multiple malformations in keeping with the VACTERL association. Molecular studies demonstrated that both are homozygous for IVS4 + 4 A T, a mutation in the Fanconi anemia complementation group C gene. This is the first molecular proof that VACTERL with hydrocephalus may be the result of severe Fanconi anemia. Am. J. Med. Genet. 68:86–90, 1997 © 1997 Wiley-Liss, Inc.

Oculodentodigital syndrome (ODD) is a congenital, autosomal dominant disorder which affects the development of the face, eyes, limbs and dentition. Spastic paraparesis is thought to be an occasional manifestation of the disorder. Type III syndactyly, which occurs as part of ODD, has also been reported to occur as an isolated entity. In the current investigation, a total genome search for the location of the ODD locus was instigated and linkage to polymorphic markers located on chromosome 6q established (pairwise Zmax = 9.37; theta = 0.001). Analysis of a large family with type III syndactyly, but atypical facial features, further suggested that isolated type III syndactyly is also located in this same region of the genome.

We describe nine children with a similar pattern of features including macrocephaly and cutis marmorata telangiectatica congenita. All were large at birth and had a distinctive capillary haemangioma involving the philtrum and upper lip. The seven who survived all developed hydrocephalus and had developmental delay. Six developed body asymmetry and three had internal arteriovenous malformations. Syndactyly of the second and third toes and/or the third and fourth fingers or toes was commonly seen. All of the cases were sporadic. This condition is easily recognizable and should be considered in the differential diagnosis of patients presenting with overgrowth and macrocephaly.

BACKGROUND: Recent reports have suggested a higher risk of Beckwith-Wiedemann syndrome (BWS) and Angelman syndrome (AS) after assisted reproductive technologies (ARTs), but it is unclear whether this might also apply to other disorders of genomic imprinting. METHODS: We contacted families of children with BWS, AS, Prader-Willi syndrome (PWS) and transient neonatal diabetes mellitus (TNDM) to determine use of ART. RESULTS: A statistically significant increased frequency of ART in children with BWS was confirmed [2.9%, 95% confidence interval (CI) 1.4-6.3% vs 0.8% expected] but there was no significant association with PWS or TNDM. Consideration of the molecular subgroup of BWS and AS suggested the feasibility of association with ART. CONCLUSIONS: These differences may relate to variations in (i) the molecular mechanisms for disordered imprinting in the different disorders and (ii) the susceptibility of specific imprinting control regions to ART-associated methylation alterations (epimutations).

Axenfeld-Rieger syndrome (ARS) is an autosomal dominant disorder with variable expressivity. It is characterized by dysgenesis of the anterior segment of the eye together with dental, cardiac, and umbilical anomalies. There is a high incidence of secondary high tension glaucoma. It is a genetically heterogeneous condition due to deletion or mutations of FOXC1 (6p25) or PITX2 (4q25). We report on four unrelated patients with overlapping microdeletions encompassing PITX2 at 4q25. We compare the genotypes and phenotypes of these newly described ARS patients and discuss the involvement of contiguous genes. Patients 1, 2, and 3 had mild learning difficulties, not typically seen in patients with ARS. We implicate the adjacent neuronally expressed genes; NEUROG2, UGT8, NDST3, and PRSS12 as potentially causal. Our findings support the use of microarray analysis in ARS patients for full prognostic information in infants presenting with ARS-like phenotypes.

The causative relationship between several of the syndromic forms of craniosynostosis and mutations in the fibroblast growth factor receptor (FGFR) loci is now well established. However, within the group of patients with craniosynostosis, there are several families and sporadic cases whose clinical features differ in variable degrees from the classically described syndromes of craniosynostosis. In this communication we present novel FGFR2 mutations associated with a spectrum of craniosynostosis phenotypes in 4 sporadic cases and in one family in which craniosynostosis segregates. The mutation and phenotype data presented emphasise the clinical variability of mutations at this locus and underline the plasticity of the phenotype-genotype relationship in this important group of congenital malformation syndromes. Mutations found were tyrosine 105 to cysteine, glycine 338 to glutamic acid, serine 351 to cysteine and glycine 384 to arginine. These are the first reported mutations in the first immunoglobulin-like loop (tyrosine 105 to cysteine) and the transmembrane domain (glycine 384 to arginine) of FGFR2, providing further insights into the mechanism of abnormal receptor function in FGFR2 mutations.

De novo germline variants in several components of the SWI/SNF-like BAF complex can cause Coffin-Siris syndrome (CSS), Nicolaides-Baraitser syndrome (NCBRS), and nonsyndromic intellectual disability. We screened 63 patients with a clinical diagnosis of CSS for these genes (ARID1A, ARID1B, SMARCA2, SMARCA4, SMARCB1, and SMARCE1) and identified pathogenic variants in 45 (71%) patients. We found a high proportion of variants in ARID1B (68%). All four pathogenic variants in ARID1A appeared to be mosaic. By using all variants from the Exome Variant Server as test data, we were able to classify variants in ARID1A, ARID1B, and SMARCB1 reliably as being pathogenic or nonpathogenic. For SMARCA2, SMARCA4, and SMARCE1 several variants in the EVS remained unclassified, underlining the importance of parental testing. We have entered all variant and clinical information in LOVD-powered databases to facilitate further genotype-phenotype correlations, as these will become increasingly important because of the uptake of targeted and untargeted next generation sequencing in diagnostics. The emerging phenotype-genotype correlation is that SMARCB1 patients have the most marked physical phenotype and severe cognitive and growth delay. The variability in phenotype seems most marked in ARID1A and ARID1B patients. Distal limbs anomalies are most marked in ARID1A patients and least in SMARCB1 patients. Numbers are small however, and larger series are needed to confirm this correlation., (undefined)

Beckwith-Wiedemann syndrome (BWS) is a model imprinting disorder resulting from mutations or epimutations affecting imprinted genes on chromosome 11p15.5.1 The classical clinical features of BWS are macroglossia, pre- and/or postnatal overgrowth, and anterior abdominal wall defects (umbilical hernia or exomphalos). Additional more variable features include hemihypertrophy, neonatal hypoglycaemia, facial naevus flammeus, ear pits and creases, renal anomalies, and an increased risk of embryonal tumours.2 Most cases of BWS are sporadic and ∼20% of these have uniparental disomy (paternal isodisomy) for a variable region of chromosome 11 which always includes the 11p15.5 imprinted gene cluster.3–5 Up to 60% of sporadic BWS patients have epigenetic changes at differentially methylated regions within 11p15.5 that are associated with alterations in the imprinting or expression of paternally expressed genes, such as IGF2 and KCNQ1OT , or maternally expressed genes, such as H19 and CDKN1C .1 Thus, 5–10% have epigenetic alterations at the IGF2 / H19 loci (the maternal H19 and IGF2 alleles display paternal allele methylation and expression patterns with biallelic IGF2 expression and silencing of H19 expression),6 and 40–50% have loss of maternal allele methylation at a differentially methylated region (KvDMR1) within an intron of KCNQ1 . KvDMR1 loss of methylation is associated with biallelic expression of KCNQ1OT .7–9 The epigenetic alterations at H19 / IGF2 or KvDMR1 are thought to result from defects at two putative imprinting control centres (BWSIC1 and BWSIC2, respectively).1 The precise nature of the putative BWSIC2 is unknown and therefore the origin of these putative BWSIC2 defects is unknown. Weksberg et al 10 showed a clear association between monozygotic twinning and BWS with KvDMR1 loss of methylation and suggested two possible explanations: (1) that discordance for BWS in monozygotic twins is caused by unequal splitting of the inner cell mass …

Background: Fraser syndrome (FS) is a autosomal recessive malformation syndrome characterised by cryptophthalmos, syndactyly and urogenital defects. FS is a genetically heterogeneous condition. Thus far, mutations in FRAS1 and FREM2 have been identified as cause of FS. Both FRAS1 and FREM2 encode extracellular matrix proteins that are essential for the adhesion between epidermal basement membrane and the underlying dermal connective tissues during embryonic development. Mutations in murine Grip1, which encodes a scaffolding protein that interacts with Fras1/Frem proteins, result in FS-like defects in mice.Objective: To test GRIP1 for genetic variants in FS families that do not have mutations in FRAS1 and FREM2.Methods and results: In three unrelated families with parental consanguinity, GRIP1 mutations were found to segregate with the disease in an autosomal recessive manner (donor splice site mutation NM_021150.3:c.2113+1G→C in two families and a 4-bp deletion, NM_021150.3:c.1181_1184del in the third). RT-PCR analysis of the GRIP1 mRNA showed that the c.2113+1G→C splice mutation causes skipping of exon 17, leading to a frame shift and a premature stop of translation.Conclusion: Mutations in GRIP1 cause classic FS in humans.

Holt–Oram syndrome (HOS) is a rare autosomal dominant heart–hand syndrome due to mutations in the TBX5 transcription factor. Affected individuals can have structural cardiac defects and/or conduction abnormalities, and exclusively upper limb defects (typically bilateral, asymmetrical radial ray defects). TBX5 mutations reported include nonsense, missense, splicing mutations and exon deletions. Most result in a null allele and haploinsufficiency, but some impair nuclear localisation of TBX5 protein or disrupt its interaction with co-factors and downstream targets. We present a five generation family of nine affected individuals with an atypical HOS phenotype, consisting of ulnar ray defects (ulnar hypoplasia, short fifth fingers with clinodactyly) and very mild radial ray defects (short thumbs, bowing of the radius and dislocation of the radial head). The cardiac defects seen are those more rarely reported in HOS (atrioventricular septal defect, hypoplastic left heart syndrome, mitral valve disease and pulmonary stenosis). Conduction abnormalities include atrial fibrillation, atrial flutter and sick sinus syndrome. TBX5 mutation screening (exons 3–10) identified no mutations. Array comparative genomic hybridisation (CGH) revealed a 48 kb duplication at 12q24.21, encompassing exons 2–9 of the TBX5 gene, with breakpoints within introns 1–2 and 9–10. The duplication segregates with the phenotype in the family, and is likely to be pathogenic. This is the first known report of an intragenic duplication of TBX5 and its clinical effects; an atypical HOS phenotype. Further functional studies are needed to establish the effects of the duplication and pathogenic mechanism. All typical/atypical HOS cases should be screened for TBX5 exon duplications.

To date, 32 cases of partial 7p monosomy have been described, 14 of which have been associated with craniosynostosis (CRS). There is considerable variation in the size and location of the deleted segment. However, CRS appears to be consistently associated with either a deletion or partial deletion 7p21-->7p22 or more rarely a deletion of 7p13-->7p14. Analysis of a panel of six 7p deletion cases (three with CRS) was undertaken using informative DNA probes, in order to characterize and define the extent of the deletions at the molecular level. There were five de novo deletions and one resulting from the unbalanced product of a paternal balanced insertion. The putative proximal CRS locus at 7p13-->7p14 does not appear to be allelic with Greig cephalopolysyndactyly syndrome. Three probe positions have been refined: pJ5.11 (D7S10) previously mapped to 7p14-->pter does not appear to map proximal to p15; TM102L (D7S135) does not map distal to p22; CRI-P137 (D7S65) maps distal to 7p13.

Item does not contain fulltext Persons with neurodevelopmental disorders or autism spectrum disorder (ASD) often harbor chromosomal microdeletions, yet the individual genetic contributors within these regions have not been systematically evaluated. We established a consortium of clinical diagnostic and research laboratories to accumulate a large cohort with genetic alterations of chromosomal region 2q23.1 and acquired 65 subjects with microdeletion or translocation. We sequenced translocation breakpoints; aligned microdeletions to determine the critical region; assessed effects on mRNA expression; and examined medical records, photos, and clinical evaluations. We identified a single gene, methyl-CpG-binding domain 5 (MBD5), as the only locus that defined the critical region. Partial or complete deletion of MBD5 was associated with haploinsufficiency of mRNA expression, intellectual disability, epilepsy, and autistic features. Fourteen alterations, including partial deletions of noncoding regions not typically captured or considered pathogenic by current diagnostic screening, disrupted MBD5 alone. Expression profiles and clinical characteristics were largely indistinguishable between MBD5-specific alteration and deletion of the entire 2q23.1 interval. No copy-number alterations of MBD5 were observed in 7878 controls, suggesting MBD5 alterations are highly penetrant. We surveyed MBD5 coding variations among 747 ASD subjects compared to 2043 non-ASD subjects analyzed by whole-exome sequencing and detected an association with a highly conserved methyl-CpG-binding domain missense variant, p.79Gly>Glu (c.236G>A) (p = 0.012). These results suggest that genetic alterations of MBD5 cause features of 2q23.1 microdeletion syndrome and that this epigenetic regulator significantly contributes to ASD risk, warranting further consideration in research and clinical diagnostic screening and highlighting the importance of chromatin remodeling in the etiology of these complex disorders.

BACKGROUND Haploinsufficiency of PMP22 causes hereditary neuropathy with liability to pressure palsies. However, the biological functions of the PMP22 protein in humans have largely been unexplored owing to the absence of patients with PMP22-null mutations. OBJECTIVE To investigate the function of PMP22 in the peripheral nervous system by studying a boy without the PMP22 gene and mice without the Pmp22 gene. DESIGN The clinical and pathological features of a patient with a PMP22 homozygous deletion are compared with those of Pmp22-null mice. SETTING Clinical evaluation was performed at tertiary hospitals in the United Kingdom. Molecular diagnosis was performed at the West Midlands Regional Genetics Laboratory. Immunohistochemistry and electron microscopy analyses were conducted at Wayne State University, Detroit, Michigan. Analysis of the Pmp22 +/- and null mice was performed at Vanderbilt University, Nashville, Tennessee. PARTICIPANT A 7-year-old boy without the PMP22 gene. RESULTS Motor and sensory deficits in the proband were nonlength-dependent. Weakness was found in cranial muscles but not in the limbs. Large fiber sensory modalities were profoundly abnormal, which started prior to the maturation of myelin. This is in line with the temporal pattern of PMP22 expression predominantly in cranial motor neurons and dorsal root ganglia during embryonic development, becoming undetectable in adulthood. Moreover, there were conspicuous maturation defects of myelinating Schwann cells; these defects were more significant in motor nerve fibers than in sensory nerve fibers. CONCLUSIONS Taken together, the data suggest that PMP22 is important for the normal function of neurons that express PMP22 during early development, such as cranial motor neurons and spinal sensory neurons. Moreover, PMP22 deficiency differentially affects myelination between motor and sensory nerves, which may have contributed to the unique clinical phenotype in the patient with an absence of PMP22.

Craniosynostosis and supernumerary teeth most often occur as isolated developmental anomalies, but they are also separately manifested in several malformation syndromes. Here, we describe a human syndrome featuring craniosynostosis, maxillary hypoplasia, delayed tooth eruption, and supernumerary teeth.We performed homozygosity mapping in three unrelated consanguineous Pakistani families and localized the syndrome to a region in chromosome 9. Mutational analysis of candidate genes in the region revealed that all affected children harbored homozygous missense mutations (c.662C>G [p.Pro221Arg], c.734C>G [p.Ser245Cys], or c.886C>T [p.Arg296Trp]) in IL11RA (encoding interleukin 11 receptor, alpha) on chromosome 9p13.3. In addition, a homozygous nonsense mutation, c.475C>T (p.Gln159X), and a homozygous duplication, c.916-924dup (p.Thr306-Ser308dup), were observed in two north European families. In cell-transfection experiments, the p.Arg296Trp mutation rendered the receptor unable to mediate the IL11 signal, indicating that the mutation causes loss of IL11RA function. We also observed disturbed cranial growth and suture activity in the Il11ra null mutant mice, in which reduced size and remodeling of limb bones has been previously described. We conclude that IL11 signaling is essential for the normal development of craniofacial bones and teeth and that its function is to restrict suture fusion and tooth number. The results open up the possibility of modulation of IL11 signaling for the treatment of craniosynostosis. © 2011 by The American Society of Human Genetics. All rights reserved.

Bilateral frontoparietal polymicrogyria is an autosomal recessive inherited human brain malformation with abnormal cortical lamination. The affected cortex appears to consist of numerous small gyri, with scalloping of the cortical-white matter junction. There are associated white matter, brain stem, and cerebellar changes. Affected individuals manifest mental retardation, language impairment, motor developmental delay, and seizure disorder. GPR56 is the causative gene. Here we report a novel missense mutation of GPR56, E496K, identified in a consanguineous pedigree with bilateral frontoparietal polymicrogyria. GPR56 protein is cleaved at the G-protein-coupled receptor proteolytic site into an N- and a C-terminal fragment, named GPR56(N) and GPR56(C), respectively. E496K is located in GPR56(C). Further biochemical studies reveal that this mutation affects GPR56(C) cell surface expression similar to the effect of a previously reported mutation, R565W. These results provide further insights into how GPR56 mutation causes neurologic disease.

MMNP; International audience; Cockayne syndrome is an autosomal recessive multisystem disorder characterized principally by neurological and sensory impairment, cachectic dwarfism, and photosensitivity. This rare disease is linked to mutations in the CSB/ERCC6 and CSA/ERCC8 genes encoding proteins involved in the transcription-coupled DNA repair pathway. The clinical spectrum of Cockayne syndrome encompasses a wide range of severity from severe prenatal forms to mild and late-onset presentations. We have reviewed the 45 published mutations in CSA and CSB to date and we report 43 new mutations in these genes together with the corresponding clinical data. Among the 84 reported kindreds, 52 (62%) have mutations in the CSB gene. Many types of mutations are scattered along the whole coding sequence of both genes, but clusters of missense mutations can be recognized and highlight the role of particular motifs in the proteins. Genotype-phenotype correlation hypotheses are considered with regard to these new molecular and clinical data. Additional cases of molecular prenatal diagnosis are reported and the strategy for prenatal testing is discussed. Two web-based locus-specific databases have been created to list all identified variants and to allow the inclusion of future reports (www.umd.be/CSA/ and www.umd.be/CSB/).

Contains fulltext : 88233.pdf (Publisher’s version ) (Closed access) Cleidocranial Dysplasia (CCD) is an autosomal dominant skeletal disorder characterized by hypoplastic or absent clavicles, increased head circumference, large fontanels, dental anomalies, and short stature. Hand malformations are also common. Mutations in RUNX2 cause CCD, but are not identified in all CCD patients. In this study we screened 135 unrelated patients with the clinical diagnosis of CCD for RUNX2 mutations by sequencing analysis and demonstrated 82 mutations 48 of which were novel. By quantitative PCR we screened the remaining 53 unrelated patients for copy number variations in the RUNX2 gene. Heterozygous deletions of different size were identified in 13 patients, and a duplication of the exons 1 to 4 of the RUNX2 gene in one patient. Thus, heterozygous deletions or duplications affecting the RUNX2 gene may be present in about 10% of all patients with a clinical diagnosis of CCD which corresponds to 26% of individuals with normal results on sequencing analysis. We therefore suggest that screening for intragenic deletions and duplications by qPCR or MLPA should be considered for patients with CCD phenotype in whom DNA sequencing does not reveal a causative RUNX2 mutation. 01 augustus 2010

Cleidocranial dysplasia is an autosomal dominant, generalised skeletal disorder characterised by variable clavicular hypoplasia, frontal bossing, multiple Wormian bones, and delayed eruption of the teeth. The gene locus for this syndrome has not yet been assigned. Three individuals with manifestations of cleidocranial dysplasia associated with rearrangements of chromosome 8q22 are described. The evidence presented suggests that the gene for cleidocranial dysplasia may be located on chromosome 8q in humans in a region showing homology to mouse chromosome 3.

[Extract] Craniosynostosis or premature closure of the cranial sutures is a common malformation occurring in approximately 1 in 2000 children. To date more than 20 cases of partial 7p monosomies have been described, approximately half of which have been associated with craniosynostosis. There is considerable variation in the size and location of the deleted segment.

We report a female fetus with occipital encephalocele, dysraphism of the cervical spine, right renal agenesis and Mullerian agenesis. Additional findings included posterior cleft palate, absent left umbilical artery and Meckel's diverticulum. This fetus had the features of MURCS association with occipital encephalocele. This is the second report of encephalocele with MURCS association.

Aristaless-related homeobox (ARX) gene mutations cause a diverse spectrum of disorders of the human brain, including lissencephaly, various forms of epilepsy and non-syndromic mental retardation. We have identified a novel mutation, c.81C>G (p.Y27X), within the ARX gene in a family with two affected male cousins. One of the boys was diagnosed with an early infantile epileptic encephalopathy also known as Ohtahara syndrome, whereas his cousin had been diagnosed with West syndrome (WS). Both patients have normal genitalia and neither have lissencephaly. The ARX mutation identified is predicted to yield a severely truncated protein of only 26 amino acids and can be considered as a null mutation. Somewhat surprisingly, however, it does not yield the X-linked lissencephaly with ambiguous genitalia (XLAG) syndrome. We proposed that the ARX mRNA translation re-initiated at the next AUG codon at position c.121-123 (aa 41) and, thus, partly rescued these patients from XLAG. Our in vitro studies show that this N-terminally truncated ARX protein (p.M41_C562) is detected by western immunoblot in lysates from cells transiently transfected with an ARX over-expression construct containing the c.81C>G mutation. Although these findings widen the spectrum of clinical phenotypes because of mutations in the ARX gene, they also emphasize the molecular pathogenetic effect of individual mutations as well as the effect of genetic background resulting in intrafamilial clinical heterogeneity for these mutations.

Merosin deficient congenital muscular dystrophy 1A (MDC1A) results from mutations in the LAMA2 gene. We report 51 patients with MDC1A and examine the relationship between degree of merosin expression, genotype and clinical features. Thirty-three patients had absence of merosin and 13 showed some residual merosin. Compared to the residual merosin group, patients with absent merosin had an earlier presentation ( P =0.0073), were more likely to lack independent ambulation ( P =0.0215), or require enteral feeding ( P =0.0099) and ventilatory support ( P =0.0354). We identified 33 novel LAMA2 mutations; these were distributed throughout the gene in patients with absent merosin, with minor clusters in exon 27, 14, 25 and 26 (55% of mutations). Patients with residual merosin often carried at least one splice site mutation and less frequently frameshift mutations. This large study identified novel LAMA2 mutations and highlights the role of immunohistochemical studies for merosin status in predicting clinical severity of MDC1A.

Aicardi-Goutieres syndrome is a mendelian mimic of congenital infection and also shows overlap with systemic lupus erythematosus at both a clinical and biochemical level. The recent identification of mutations in TREX1 and genes encoding the RNASEH2 complex and studies of the function of TREX1 in DNA metabolism have defined a previously unknown mechanism for the initiation of autoimmunity by interferon-stimulatory nucleic acid. Here we describe mutations in SAMHD1 as the cause of AGS at the AGS5 locus and present data to show that SAMHD1 may act as a negative regulator of the cell-intrinsic antiviral response.

Contains fulltext : 80656.pdf (Publisher’s version ) (Closed access) BACKGROUND: The 9q subtelomeric deletion syndrome (9qSTDS) is clinically characterised by moderate to severe mental retardation, childhood hypotonia and facial dysmorphisms. In addition, congenital heart defects, urogenital defects, epilepsy and behavioural problems are frequently observed. The syndrome can be either caused by a submicroscopic 9q34.3 deletion or by intragenic EHMT1 mutations leading to haploinsufficiency of the EHMT1 gene. So far it has not been established if and to what extent other genes in the 9q34.3 region contribute to the phenotype observed in deletion cases. This study reports the largest cohort of 9qSTDS cases so far. METHODS AND RESULTS: By a multiplex ligation dependent probe amplification (MLPA) approach, the authors identified and characterised 16 novel submicroscopic 9q deletions. Direct sequence analysis of the EHMT1 gene in 24 patients exhibiting the 9qSTD phenotype without such deletion identified six patients with an intragenic EHMT1 mutation. Five of these mutations predict a premature termination codon whereas one mutation gives rise to an amino acid substitution in a conserved domain of the protein. CONCLUSIONS: The data do not provide any evidence for phenotype-genotype correlations between size of the deletions or type of mutations and severity of clinical features. Therefore, the authors confirm the EHMT1 gene to be the major determinant of the 9qSTDS phenotype. Interestingly, five of six patients who had reached adulthood had developed severe psychiatric pathology, which may indicate that EHMT1 haploinsufficiency is associated with neurodegeneration in addition to neurodevelopmental defect.

We describe two children with multiple abnormalities, neither of whom fits neatly into a classical diagnostic category, but who show overlapping features of Ellis-van Creveld syndrome, Jeune syndrome, and renal-hepatic-pancreatic dysplasia. It seems possible that these three entities form part of a disease spectrum rather than being distinct conditions.

Relatively, few reports of deletions involving the distal long arm of chromosome 4 (4q) exist. Five further cases are described and the findings are compared with those in previous literature reports. Distal 4q deletions may be recognized by the distinctive appearance of the fifth finger, which is stiff with a hypoplastic distal phalanx and a hooked or volar nail. All cases with this characteristic fifth finger anomaly appear to have deletions involving 4q34.

Contains fulltext : 48832.pdf (Publisher’s version ) (Closed access) Mutations in the GLI3 zinc-finger transcription factor gene cause Greig cephalopolysyndactyly syndrome (GCPS) and Pallister-Hall syndrome (PHS), which are variable but distinct clinical entities. We hypothesized that GLI3 mutations that predict a truncated functional repressor protein cause PHS and that functional haploinsufficiency of GLI3 causes GCPS. To test these hypotheses, we screened patients with PHS and GCPS for GLI3 mutations. The patient group consisted of 135 individuals: 89 patients with GCPS and 46 patients with PHS. We detected 47 pathological mutations (among 60 probands); when these were combined with previously published mutations, two genotype-phenotype correlations were evident. First, GCPS was caused by many types of alterations, including translocations, large deletions, exonic deletions and duplications, small in-frame deletions, and missense, frameshift/nonsense, and splicing mutations. In contrast, PHS was caused only by frameshift/nonsense and splicing mutations. Second, among the frameshift/nonsense mutations, there was a clear genotype-phenotype correlation. Mutations in the first third of the gene (from open reading frame [ORF] nucleotides [nt] 1-1997) caused GCPS, and mutations in the second third of the gene (from ORF nt 1998-3481) caused primarily PHS. Surprisingly, there were 12 mutations in patients with GCPS in the 3' third of the gene (after ORF nt 3481), and no patients with PHS had mutations in this region. These results demonstrate a robust correlation of genotype and phenotype for GLI3 mutations and strongly support the hypothesis that these two allelic disorders have distinct modes of pathogenesis.

Lethal multiple pterygium syndrome (LMPS) is an uncommon fetal-onset disorder of unknown etiology. The pathogenesis of LMPS has been suggested to be early-onset fetal akinesia, fragile collagen, or generalized edema. Information on the neuromuscular pathology of LMPS in the literature is generally scanty. We present the findings from a review of 14 fetuses with features of LMPS from the archives of the Hammersmith Hospital Perinatal Pathology Department. Autopsy reports, photographs, fetograms, and histological sections were examined, and additional special stains and immunostaining were performed on muscle sections. In five cases, there was evidence of autosomal recessive inheritance. One case was later shown to be due to glycogen storage disease type IV. The skeletal muscle bulk was reduced in all fetuses and the remaining muscle showed a range of histological appearances including vacuolar degeneration, dystrophy, a generalized or patchy myotubular appearance, and generalized hypotrophy. In one, the histological appearance was essentially normal. Two cases had abnormalities in the brain. Large motor neurons were present in the anterior spinal horns of all fetuses in whom the spinal cord could be examined. There was no evidence of cartilaginous joint fusion. We conclude that LMPS is the phenotype resulting from fetal akinesia commencing in the first or early second trimester. In the majority of cases, the precise underlying cause will not be identified, however, occasionally a metabolic or neurodevelopmental disorder or a specific primary myopathy may be demonstrated, providing adequate autopsy investigations are undertaken.

Michael Absoud, Louise Brueton, Rajat Gupta, Ros Quinlivan, Evangeline Wassmer 1 Institute of Child Health, Birmingham Children's Hospital, Birmingham, UK. 2 Clinical Genetics Unit, West Midlands Regional Clinical Genetics Service, Birmingham Women's NHS Foundation Trust. Birmingham, UK. 3 Paediatric Neurology Department, Birmingham Children's Hospital, Birmingham, UK. Correspondence to: evangeline.wassmer@bch.nhs.uk

The transcription factor TFIIH is involved in both basal transcription and DNA repair. Mutations in the XPD helicase component of TFIIH can result in the diverse clinical features associated with xeroderma pigmentosum (XP) and trichothiodystrophy (TTD). It is generally believed that the multi-system abnormalities associated with TTD are the result of a subtle deficiency in basal transcription. However, to date, there has been no clear demonstration of a defect in expression of any specific gene in individuals with these syndromes. Here we show that the specific mutations in XPD that cause TTD result in reduced expression of the beta-globin genes in these individuals. Eleven TTD patients with characterized mutations in the XPD gene have the haematological features of beta-thalassaemia trait, and reduced levels of beta-globin synthesis and beta-globin mRNA. All these parameters were normal in three patients with XP. These findings provide the first evidence for reduced expression of a specific gene in TTD. They support the hypothesis that many of the clinical features of TTD result from inadequate expression of a diverse set of highly expressed genes.