GENETICS OF X-LINKED CONGENITAL CEREBELLAR HYPOPLASIA

Congenital ataxias (CA) represent 10% of all nonprogressive encefalopathies affecting pediatric patients. The genetic aspects of CA have not been sufficiently investigated and no gene involved in human cerebellum (mal)development has been yet identified. Moreover the clinical diagnosis of CA is not and easy task, due to the aspecifity of clinical symptoms preceding the ataxia: congenital muscular hypotonia, psychomotor retardation Congenital ataxias of genetic are classified into 2 main groups: monosintomatic forms due to isolated cerebellar malformations: cerebellar hypoplasia/atrophy,Dandy-Walker malformation. The multisistemic or syndromal forms in which the cerebellar malformation is associated with other malformations ( cardiac, renal, hepatic, ocular) and/or mental retardation. X-Iinked congenital ataxia/cerebellar hypoplasia (XCA) is characterized by severe hypotonia at birth, delayed early motor development, dysarthria, slow eye movements and nonprogressive cerebellar ataxia with normal/borderline intelligence. The objective of our study is to identify the gene causing XCA, analyzing 4 families (more than 72 individuals, 10 affected) The expected risults will undoubtedly improve our understanding of the mechanisms underlying cerebellum development and will allow molecular genetic diagnostic confirmation (or exclusion)of XCA in familiar and sporadic cases of males presenting with an isolated cerebellar malformation(hypoplasia/atrophy).