Maw M A, John S, Jablonka S, Müller B, Kumaramanickavel G, Oehlmann R, Denton M J, Gal A
Biochemistry Department, University of Otago, Dunedin, New Zealand.
J Med Genet. 1995 May;32(5):396-8. doi: 10.1136/jmg.32.5.396.
Oguchi disease is a rare autosomal recessive form of congenital stationary night blindness. The condition is associated with fundus discolouration and abnormally slow dark adaptation. Earlier studies suggested that the 48 kD protein S antigen may be involved in the recovery phase of light transduction. Previous cytogenetic and linkage studies have localised the S antigen gene (SAG) to chromosome 2q37.1. In the present study markers which map to distal chromosome 2q were typed in an inbred Oguchi pedigree. The segregation data obtained suggested that the affected subjects are homozygous by descent for a region between D2S172 and D2S345. An intragenic SAG polymorphism was homozygous in all affected people and a recombination event suggested that SAG maps proximal to D2S345. Collectively, these findings support the hypothesis that a defect in S antigen may be responsible for Oguchi disease.
小口病是一种罕见的常染色体隐性先天性静止性夜盲症。该病与眼底变色和异常缓慢的暗适应有关。早期研究表明，48 kD蛋白S抗原可能参与光转导的恢复阶段。先前的细胞遗传学和连锁研究已将S抗原基因（SAG）定位到2q37.1染色体。在本研究中，对一个近亲小口病家系进行了定位到2q染色体远端的标记分型。获得的分离数据表明，患病个体在D2S172和D2S345之间的区域通过遗传是纯合的。所有患病个体中一个基因内SAG多态性是纯合的，并且一次重组事件表明SAG位于D2S345近端。总体而言，这些发现支持S抗原缺陷可能是小口病病因的假说。
