Benign hereditary chorea of early onset maps to chromosome 14q

Benign hereditary chorea (BHC) is an autosomal dominant disorder characterized by an early-onset nonprogressive chorea. The early onset and the benign course distinguishes BHC from the more common Huntington disease (HD). Previous studies on families with BHC have shown that BHC and HD are not allelic. We studied a large Dutch kindred with BHC and obtained strong evidence for linkage between the disorder and markers on chromosome 14q (maximum LOD score 6.32 at recombination fraction 0). The BHC locus in this family was located between markers D14S49 and D14S1064, a region spanning approximately 20.6 cM that contains several interesting candidate genes involved in the development and/or maintenance of the CNS: glia maturation factor-beta, GTP cyclohydrolase 1 and the survival of motor neurons (SMN)-interacting protein 1. The mapping of the BHC locus to 14q is a first step toward identification of the gene involved, which might, subsequently, shed light on the pathogenesis of this and other choreatic disorders.