X-linked Retinoschisis
A case report and genetic diagnosis analysis
Abstract
X-linked Retinoschisis is a genetic disease characterized by
reduced visual acuity in men due to juvenile macular degeneration.
Its prevalence is 1/5000 men worldwide. It manifests from the first
decade of life with loss of vision that progresses to adolescence and
then remains stable until the 4th decade of life, when it may present
a significant decline. The fundus exam usually shows schism. Carrier
women rarely have symptoms. The gene involved is RS1 (Xp22.13),
which codes for Retinoschisin, a protein that participates in the
structural and functional integrity of the retina. In affected cases
mutations that generate loss of protein function were demonstrated.
The diagnosis is based on the clinical and family history, and is
supported by ophthalmology evaluation; in most cases it can be
confirmed by sequencing of the gene. The treatment consists of
periodic ophthalmological control and surgery of the complications.
We describe the case of a 2 year old boy with repeated episodes
of retinal detachment and who has a family history of Retinoschisis
by maternal line in male individuals. These were studied, and it was
shown that they are carriers of the probably pathogenic variant
c.466A> C (Arg156Gly) in the RS1 gene, which had been reported
previously in a family of Chinese origin. It was shown that our
patient presents the family mutation in hemizygous state, so this is the second family in which the segregation of this variant with
Retinoschisis is confirmed.
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