Nonprogressive autosomal recessive ataxia maps to chromosome 9q34-9qter ina large consanguineous Lebanese family

Congenital ataxias are a heterogeneous group of predominantly nonprogressiv e disorders characterized by hypotonia, developmental delay followed by the appearance of ataxia, and often associated with dysarthria, mental retarda tion, and atrophy of the cerebellum. We performed a genome-wide screen on a large inbred Lebanese family presenting a nonprogressive autosomal recessi ve congenital cerebellar ataxia associated with short stature (MIM 213200), already described by Megarbane and colleagues. The disease locus was assig ned to a 12.1 cM interval on chromosome 9q34-9qter between D9S67 and D9S312 . Differential diagnosis with other hereditary ataxias linked to the same r egion is discussed.