Congenital stationary night blindness: report of an autosomal recessive family and linkage analysis.
Congenital stationary night blindness (CSNB) is a group of rare, non-progressive conditions of the retina characterized by abnormal rod function causing impaired night vision. Among them, the Schubert-Bornschein subgroup, itself divided into a complete and an incomplete form, is characterized by a specific electrophysiological pattern. Complete, Schubert-Bornschein CSNB is usually transmitted as a monogenic trait, and most familial cases result from mutations of the NYX gene located on the X chromosome. We report a very rare family with consanguineous, first-cousin parents, where a son and a daughter are affected with this condition, indicating autosomal recessive inheritance. As the family was too small for genome-wide linkage, we considered several candidate loci, including the sidekick SDK1 and SDK2 genes. The latter determine lamina-specific connectivity in the retina, a histological substrate of the ON pathway implicated in complete, Schubert-Bornschein CSNB. Although linkage was excluded in our family, observations like the present one may lead to the identification of a new molecular cause for this condition.
Abramowicz
Marc J
MJ
Service de Génétique Médicale, Hôpital Erasme and Laboratoire de Génétique Médicale-ULB, Brussels, Belgium. marcabra@ulb.ac.be
Ribai
Pascale
P
Cordonnier
Monique
M
D002675:Child, Preschool; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics; D041321:Chromosomes, Human, X / Q000235:genetics; D003241:Consanguinity; D004252:DNA Mutational Analysis; D005192:Family Health; D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1; D005808:Genes, Recessive / Q000235:genetics*; D008040:Genetic Linkage; D006239:Haplotypes; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D009419:Nerve Tissue Proteins / Q000235:genetics; D009755:Night Blindness / Q000151:congenital / Q000235:genetics*; D010375:Pedigree; D016601:RNA-Binding Proteins / Q000235:genetics; D011944:Receptors, Androgen / Q000235:genetics; D018911:Trinucleotide Repeats / Q000235:genetics
D051860:Fragile X Messenger Ribonucleoprotein 1; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; D011944:Receptors, Androgen; C497683:FMR1 protein, human