The four-generation family with MRX87 haplotypes for markers in Xp22-p21 and segregation of ARX mutation. Thirteen individuals from whom DNA was available were genotyped and linkage analysis was performed. Informative recombinations between the markers DXS987 and DXS207 and between DXS1061 and DXS1214 are indicated with the arrowheads. X disease haplotype (Xd) is shown in red. The X inactivation ratio, obtained by HUMARA (Human Androgen Receptor gene, AR) assay is indicated for each woman tested. The physical order of the markers analysed is, from telomere (top) to the centromere (bottom), as shown.