Posthumous diagnosis of X-linked retinoschisis using DNA analysis.

X-linked juvenile retinoschisis usually results in a rather serious visual handicap in affected males. However, occasionally patients can present with very subtle clinical signs without subjective complaints. For this reason, the family history can be misleading and caution is necessary when analysing the pedigree and giving genetic advice. In this report a family with X-linked retinoschisis is described in which segregation analysis with DNA probes strongly suggests that the deceased grandfather, who was said to have had good vision, had been affected by juvenile retinoschisis.