Norrie disease in a family with a manifesting female carrier
K. B. Sims, A. R. Irvine and W. V. Good
Developmental Neurogenetics Laboratories, Massachusetts General Hospital, Charlestown, USA.
OBJECTIVES: To show that Norrie disease can occur in a girl and to describe
her ophthalmologic and genetic features. METHODS: Amplification of DNA
polymerase chain reaction and sequencing of asymmetric polymerase chain
reaction for exon 3 were performed on the blood specimen obtained from a
girl born with bilateral retinal detachments. PATIENT: A female child with
bilateral retinal detachment who had 2 uncles in whom Norrie disease had
already been diagnosed. RESULTS: The child had a mutation in the third exon
(T776-->A; Ile 123-->Asn) identical to the mutation found in her
uncles. CONCLUSIONS: Norrie disease can occur in girls. The most likely
explanation is nonrandom or unfavorable X inactivation, although timing of
development of the peripheral retina and its blood supply could render it
vulnerable to effects of the mutant allele at a critical developmental
phase.
