Novel types of mutation in the choroideremia ( CHM) gene: a full-length L1 insertion and an intronic mutation activating a cryptic exon.

Choroideremia (CHM) is a progressive chorioretinal degeneration caused by mutations in the widely expressed CHM gene on chromosome Xq21. The product of this gene, Rab escort protein (REP)-1, is involved in the posttranslational lipid modification and subsequent membrane targeting of Rab proteins, small GTPases that play a key role in intracellular trafficking. We have searched for mutations of the CHM gene in patients with choroideremia by analysis of individual CHM exons and adjacent intronic sequences PCR-amplified from genomic DNA and by reverse transcription (RT)-PCR analysis of the coding region of the CHM mRNA.

Central areolar choroidal dystrophy associated with dominantly inherited drusen.

Aim: To describe the clinical and genetic aspects of a retinal dystrophy that combines central areolar choroidal dystrophy (CACD) and autosomal dominantly inherited drusen.

Methods: The members of three unrelated families who demonstrated the rare combination of CACD and dominant drusen were clinically and angiographically investigated. In addition, DNA samples from the members of these families were screened for the Arg142Trp mutation in the peripherin/retinal degeneration slow (RDS) gene.