LOCALIZATION OF A NOVEL X-LINKED CONGENITAL STATIONARY NIGHT BLINDNESS LOCUS - CLOSE LINKAGE TO THE RP3 TYPE RETINITIS-PIGMENTOSA GENE REGION

X-linked congenital stationary night blindness (CSNBX) is a non-progre ssive retinal disorder characterized by decreased visual acuity and lo ss of night vision. CSNBX is clinically heterogeneous with respect to the involvement of retinal rods and/or cones in the disease. In this s tudy, we localize a new locus for CSNBX to Xp21.1, thus providing evid ence that CSNBX is also genetically heterogeneous. A clear correlation between different genotypes and phenotypes cannot be found yet, The n ew CSNBX gene described here is closely linked to the X-linked retinit is pigmentosa type 3 gene region, which supports the hypothesis that t here may be a functional relationship between congenital stationary ni ght blindness and retinitis pigmentosa.