Utility of whole exome sequencing for the early diagnosis of pediatric-onset cerebellar atrophy associated with developmental delay in an inbred population

Archive ouverte

Megahed, Hisham | Nicouleau, Michaël | Barcia, Giulia | Medina-Cano, Daniel | Siquier-Pernet, Karine | Bole-Feysot, Christine | Parisot, Mélanie | Masson, Cécile | Nitschké, Patrick | Rio, Marlène | Bahi-Buisson, Nadia | Desguerre, Isabelle | Munnich, Arnold | Boddaert, Nathalie | Colleaux, Laurence | Cantagrel, Vincent

Edité par CCSD ; BioMed Central -

International audience. AbstractBackgroundCerebellar atrophy and developmental delay are commonly associated features in large numbers of genetic diseases that frequently also include epilepsy. These defects are highly heterogeneous on both the genetic and clinical levels. Patients with these signs also typically present with non-specific neuroimaging results that can help prioritize further investigation but don’t suggest a specific molecular diagnosis.MethodsTo genetically explore a cohort of 18 Egyptian families with undiagnosed cerebellar atrophy identified on MRI, we sequenced probands and some non-affected family members via high-coverage whole exome sequencing (WES; >97 % of the exome covered at least by 30x). Patients were mostly from consanguineous families, either sporadic or multiplex. We analyzed WES data and filtered variants according to dominant and recessive inheritance models.ResultsWe successfully identified disease-causing mutations in half of the families screened (9/18). These mutations are located in seven different genes, PLA2G6 being the gene most frequently mutated (n = 3). We also identified a recurrent de novo mutation in the KIF1A gene and a molybdenum cofactor deficiency caused by the loss of the start codon in the MOCS2A open-reading frame in a mildly affected subject.ConclusionsThis study illustrates the necessity of screening for dominant mutations in WES data from consanguineous families. Our identification of a patient with a mild and improving phenotype carrying a previously characterized severe loss of function mutation also broadens the clinical spectrum associated with molybdenum cofactor deficiency.

Suggestions

Du même auteur

Utility of whole exome sequencing for the early diagnosis of pediatric-onset cerebellar atrophy associated with developmental delay in an inbred population

Archive ouverte | Megahed, Hisham | CCSD

International audience. Background: Cerebellar atrophy and developmental delay are commonly associated features in large numbers of genetic diseases that frequently also include epilepsy. These defects are highly he...

De novo mutation screening in childhood-onset cerebellar atrophy identifies gain-of-function mutations in the CACNA1G calcium channel gene

Archive ouverte | Chemin, Jean | CCSD

IF 10.848. International audience. Cerebellar atrophy is a key neuroradiological finding usually associated with cerebellar ataxia and cognitive development defect in children. Unlike the adult forms, early onset ce...

MINPP1 prevents intracellular accumulation of the chelator inositol hexakisphosphate and is mutated in Pontocerebellar Hypoplasia

Archive ouverte | Ucuncu, Ekin | CCSD

International audience. Inositol polyphosphates are vital metabolic and secondary messengers, involved in diverse cellular functions. Therefore, tight regulation of inositol polyphosphate metabolism is essential for...

Chargement des enrichissements...