In a large Finnish family with CORDX3, previously reported by Jalkanen et al. (2003), Jalkanen et al. (2006) identified a splice site mutation in the CACNA1F gene (300110.0007). The mutation cosegregated completely with the disease phenotype in the ... In a large Finnish family with CORDX3, previously reported by Jalkanen et al. (2003), Jalkanen et al. (2006) identified a splice site mutation in the CACNA1F gene (300110.0007). The mutation cosegregated completely with the disease phenotype in the family, which included 7 affected males, 10 carrier females, and 33 unaffected family members; it was not found in 200 control chromosomes. RNA studies revealed that the mutation caused altered splicing of the CACNA1F transcript, resulting in 5 variants with predicted premature termination and exonic deletions of the encoded protein. Noting that most mutations in CACNA1F had previously been identified in patients with congenital stationary night blindness-2 (CSNB2; 300071), Jalkanen et al. (2006) stated that CORDX3 is distinguishable from CSNB2 in that it is progressive, can begin in adulthood, has no nystagmus or hyperopic refraction, has only low grade astigmatism, and in dark adaptation lacks cone threshold and has small or no elevation of rod threshold.