Microdeletion in the X‐chromosome and prenatal diagnosis in a family with Norrie disease

We have studied a three-generation family in which Norrie disease is segregating and have performed prenatal diagnosis on the fetus of an obligatory carrier. Deletions at loci DXS7 and DXS77 defined by probes L1.28, L1.28-p59, and pX59 were detected in the affected male. DNA studies of chorionic villus biopsy material indicated that the male fetus had inherited the normal allele from the carrier mother. This prediction was confirmed on eye examination at age 5 months.