CHOROIDEREMIA IS LINKED TO THE RESTRICTION FRAGMENT LENGTH POLYMORPHISM DXYS1 AT XQ13-21

  • 1 January 1985
    • journal article
    • research article
    • Vol. 37  (3) , 473-481
Abstract
Choroideremia (McK30310), an X-linked hereditary retinal dystrophy, causes night-blindness, progressive peripheral visual field loss and, ultimately, central blindness in affected males. The location of choroideremia on the X chromosome is unknown. Restriction fragment length polymorphisms from the X chromosome were used to determine the regional localization of choroideremia by linkage analysis in families with this disease. One such polymorphic locus, DXYS1, located on the long arm (Xq) within bands q13-q21, shows no recombination with choroideremia at lod = 5.78. With 90% probability, choroideremia maps within 9 centiMorgans (cM) of DXYS1. Another polymorphic locus, DXS11, located within Xq24-q26, also shows no recombination with choroideremia, although at a smaller lod score of 1.54 (90% probability limit .theta. < 30 cM). This linkage with DXS11, a marker that is distal to DXYS1, suggests that the locus for choroideremia is also distal to DXYS1 and lies between these 2 markers in the region Xq13-q24. These results provide regional mapping for the disease that may be useful for prenatal diagnosis and, perhaps ultimately, for isolating the gene locus for choroideremia.