Genetic analysis of choroideremia families in the Australian population

Choroideremia is an X-linked inherited chorioretinal disease known to be caused by mutations in the CHM gene. In this study, Australian families clinically diagnosed with choroideremia were genetically analysed for mutations in the CHM gene.

The Australian Inherited Retinal Disease Register and DNA Bank (AIRDR) was investigated to identify a cohort of choroideremia-affected families for genetic analysis.

Participants were sourced from the AIRDR. Thirty-two participants (15 affected, 10 carriers, 7 unaffected) sourced from 11 unrelated families having at least one member clinically diagnosed with choroideremia were included in the study.

We performed sequence analysis of the CHM gene on the DNA of nine probands. We received the direct sequencing results of two probands by other means. Targeted analysis was subsequently performed for all 32 participants to confirm the direct sequencing results in the 11 probands and to establish the presence or absence of the implicated mutation in the remaining 21 affected, carrier or unaffected family members.

Genetic characterisation of 11 choroideremia families in the Australian population.

A CHM mutation was detected in all 11 families. Each family had a different mutation. Mutations segregated within each family according to disease status. Five mutations were novel and six have been previously reported.

Six previously reported and five novel CHM mutations were detected in 11 Australian families clinically diagnosed with choroideremia. We anticipate that this work will facilitate access for AIRDR participants and their progeny to CHM gene therapy trials.