0000000000331027
AUTHOR
Bénédicte Demeer
Diagnostic strategy in segmentation defect of the vertebrae: a retrospective study of 73 patients
BackgroundSegmentation defects of the vertebrae (SDV) are non-specific features found in various syndromes. The molecular bases of SDV are not fully elucidated due to the wide range of phenotypes and classification issues. The genes involved are in the Notch signalling pathway, which is a key system in somitogenesis. Here we report on mutations identified in a diagnosis cohort of SDV. We focused on spondylocostal dysostosis (SCD) and the phenotype of these patients in order to establish a diagnostic strategy when confronted with SDV.Patients and methodsWe used DNA samples from a cohort of 73 patients and performed targeted sequencing of the five known SCD-causing genes (DLL3,MESP2,LFNG,HES7…
ALDH1A3 Mutations Cause Recessive Anophthalmia and Microphthalmia
Anophthalmia and microphthalmia (A/M) are early-eye-development anomalies resulting in absent or small ocular globes, respectively. A/M anomalies occur in syndromic or nonsyndromic forms. They are genetically heterogeneous, some mutations in some genes being responsible for both anophthalmia and microphthalmia. Using a combination of homozygosity mapping, exome sequencing, and Sanger sequencing, we identified homozygosity for one splice-site and two missense mutations in the gene encoding the A3 isoform of the aldehyde dehydrogenase 1 (ALDH1A3) in three consanguineous families segregating A/M with occasional orbital cystic, neurological, and cardiac anomalies. ALDH1A3 is a key enzyme in the…
Whole genome paired-end sequencing elucidates functional and phenotypic consequences of balanced chromosomal rearrangement in patients with developmental disorders
BackgroundBalanced chromosomal rearrangements associated with abnormal phenotype are rare events, but may be challenging for genetic counselling, since molecular characterisation of breakpoints is not performed routinely. We used next-generation sequencing to characterise breakpoints of balanced chromosomal rearrangements at the molecular level in patients with intellectual disability and/or congenital anomalies.MethodsBreakpoints were characterised by a paired-end low depth whole genome sequencing (WGS) strategy and validated by Sanger sequencing. Expression study of disrupted and neighbouring genes was performed by RT-qPCR from blood or lymphoblastoid cell line RNA.ResultsAmong the 55 pat…
Pseudohypoparathyroïdie : Distorsion du ratio de transmission maternelle des mutations perte de fonction de GNAS
National audience; La PseudoHypoParathyroïdie de type 1A (PHP1A) et la PseudoPseudoHypoparathyroïdie (PPHP) sont deux maladies rares à transmission autosomique dominante provoquées par des mutations perte de fonction du gène GNAS soumis à empreinte, codant la protéine Gsα. La PHP1A est causée par des mutations sur l’allèle maternel et entraîne une Ostéodystrophie Héréditaire d’Albright (AHO) et une résistance à la PTH, tandis que la PPHP avec AHO et sans résistance hormonale est liée à des mutations de l’allèle paternel. Cette étude visait à étudier la transmission des mutations de GNAS. Nous avons mené une étude rétrospective sur un grand nombre de familles mutées GNAS. Pour éviter un biai…
Mutations inWNT10Aare frequently involved in oligodontia associated with minor signs of ectodermal dysplasia
Ectodermal dysplasias (ED) are a clinically and genetically heterogeneous group of hereditary disorders that have in common abnormal development of ectodermal derivatives. Hypohidrotic ectodermal dysplasia (HED) is characterized by abnormal development of eccrine sweat glands, hair, and teeth. The X-linked form of the disease, caused by mutations in the EDA gene, represents the majority of patients with the hypohidrotic form. Autosomal dominant and autosomal recessive forms are occasionally seen, and result from mutations in at least three genes (WNT10A, EDAR, or more rarely EDARADD). We have screened for mutations in EDAR (commonly involved in the hypohidrotic form) and WNT10A (involved in…