Genetic analysis of choroideremia families in the Australian population.

BACKGROUND: 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. DESIGN: The Australian Inherited Retinal Disease Register and DNA Bank (AIRDR) was investigated to identify a cohort of choroideremia-affected families for genetic analysis. PARTICIPANTS: 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. METHODS: 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. MAIN OUTCOME MEASURES: Genetic characterisation of 11 choroideremia families in the Australian population. RESULTS: 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. CONCLUSIONS: 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.

A computer-assisted method for pathogenicity assessment and genetic reporting of variants stored in the Australian Inherited Retinal Disease Register.

The assignment of pathogenicity to variants suspected of causing an inherited retinal disease and the subsequent creation of molecular genetic reports sent to clinical geneticists and ophthalmologists has traditionally been time-consuming and subject to error and ambiguity. The purpose of this paper is to describe a computer-assisted method we have developed for (1) assessment of the predicted pathogenicity of genetic variants identified in patients diagnosed with an inherited retinal disease and (2) the incorporation of these results into the Australian Inherited Retinal Disease Register and DNA Bank's databases, for the production of molecular genetics reports. This method has significantly accelerated the assessment of variant pathogenicity prediction and subsequent patient report generation for the Australian Inherited Retinal Disease Register and DNA Bank, and has reduced the potential for human error. The principles described in this paper may be applied in any situation where genetic variants and patient information are stored in a well-organised database.