Figure 3. Characterization of a family with X-linked retinitis pigmentosa and variable expressivity in mutation carriers. A: Pedigree with three generations. Circles represent females and squares represent males. Slashed symbols indicate deceased family members. Filled black symbols denote family members with retinitis pigmentosa (RP), and circles with a dot indicate female mutation carriers who had no history of visual complaints. Horizontal bars designate family members whose genotype was determined by molecular genetic testing. Arrow marks the index patient 25085. The mutation c.2405_2406delAG in exon ORF15 of RPGR segregates with the disease in males, and shows variable heterozygote manifestation in females. B: Fundus pictures of three affected family members show typical pigmentations found in the peripheral retina of patients with RP. Patient age and gender are provided below each fundus photograph. C: Pattern of X-chromosome inactivation of selected female family members. None showed a unilateral X-inactivation at the AR-locus. The following abbreviations and symbols are used: control nonrandom X-inactivation (C-nr), control random X-inactivation (C-r), HpaII digestion (+), and no HpaII digestion (-).