Molecular analysis of the NDP gene in two families with Norrie disease.

. Purpose: To describe the molecular defects in the Norrie disease protein (NDP) gene in two families with Norrie disease (ND). Methods: We analysed two families with ND at molecular level through polymerase chain reaction, DNA sequence analysis and GeneScan. Results: Two molecular defects found in the NDP gene were: a missense mutation (265C > G) within codon 97 that resulted in the interchange of arginine by proline, and a partial deletion in the untranslated 3′ region of exon 3 of the NDP gene. Clinical findings were more severe in the family that presented the partial deletion. We also diagnosed the carrier status of one daughter through GeneScan; this method proved to be a useful tool for establishing female carriers of ND. Conclusion: Here we report two novel mutations in the NDP gene in Mexican patients and propose that GeneScan is a viable mean of establishing ND carrier status.