A gene for X-linked idiopathic congenital nystagmus (NYS1) maps to chromosome Xp11.4-p11.3

Congenital nystagmus (CN) is a common oculomotor disorder (frequency of 1/1 ,500 live births) characterized by bilateral uncontrollable ocular oscillat ions, with onset typically at birth or within the first few months of life. This condition is regarded as idiopathic, after exclusion of nervous and o cular diseases. X-linked, autosomal dominant, and autosomal recessive modes of inheritance have been reported, but X-linked inheritance is probably th e most common. In this article, we report the mapping of a gene for X-linke d dominant CN (NYS1) to the short arm of chromosome X, by showing close lin kage of NYS1 to polymorphic markers on chromosome Xp11.4-p11.3 (maximum LOD score of 3.20, over locus DXS993). Because no candidate gene, by virtue of its function, has been found in this region of chromosome Xp, further stud ies are required, to reduce the genetic interval encompassing the NYS1 gene . It is hoped that the complete gene characterization will address the comp lex pathophysiology of CN.