In addition, reported pathogenic changes in the gene are clustered in regions affecting calcium sensitivity3; this substitution occurs in an earlier part of the protein, and biochemical studies have shown that the p.(Pro50Leu) variant is not associated with calcium sensitivity (although the protein shows less thermal stability and greater susceptibility to protease digestion).7 Pathogenic variants in GUCA1A also are not associated with the RP phenotype, which was exhibited by an affected relative of the proband. The gene discussed is GUCA1A; the disease is retinitis pigmentosa 1.