Figure 1: A Chinese family with X-linked infantile nystamus. Squares are males, circles are females, filled symbols are affected individuals, dotted circles are female carriers, a diagonal line through a symbol indicates a deceased family member, and the arrow indicates the proband. The plus sign indicates individuals who underwent DNA sequencing. The number of the microsatellite used indicates the alleles at each locus. The family is inherited as the x-linked trait with non-complete penetrance because the female individual III3,III7,IV2,and IV3 are the affected females while their mothers, individual II2,II4, and III5, are the female carriers.