The Assignment of the Gene Responsible for Congenital Cataract and Micropthalmia to the Pericentromeric Region of the X Chromosome and Examination of Candidate Genes

Abstract Background: X-linked diseases are single gene disorders that are due to the presence of mutations in genes that reside on the X chromosome. X-linked recessive disorders are predicted from the family structure, where only boys are affected and there is no father to son transmission of the mutant allele. Heterozygous females are usually non-symptomatic carriers but can manifest a milder form of the disease. The identification of the genetic defect in X-linked disorders facilitates the diagnosis of affected individuals, aid in providing informative counseling and may help in prenatal diagnosis. Objectives: The study aims at mapping and identification of one gene responsible for congenital cataract and micropthalmia in a three-generation family. Methods: We recruited 12 members of a family with a clear X-linked pattern of inheritance with three affected males, all showing congenital cataracts and microphthalmia. Gene mapping was attempted using a set of microsatellite markers selected to cover the wh...