Parents

Clinical features
Mutations in ARL6 gene may lead to one of two constellation of birth defects in humans termed Bardet-Biedl syndrome 3 (BBS3) and retinitis pigmentosa 55 (RP55). These birth defects are highly variable in severity but primarily share a characteristic degeneration of the eye pigments (termed retinitis pigmentosa) which can lead to decreased vision and night blindness. BBS3 commonly has other associated clinical manifestations, such as obesity, increased number of fingers in the hands or feet, developmental delay, intellectual disability, as well as increased risk of hypertension, diabetes, and congenital heart disease. RP55 on the other hand is the “nonsyndromic” form of ARL6-associated diseases, meaning that it manifests as isolated retinitis pigmentosa (without any additional clinical manifestations).

Prevalence
Largely unknown due to limited data.

Inheritance
Mutations of this gene can be passed on to the next generation in an autosomal recessive manner. This means that if both parents carry a mutation involving this gene (usually without displaying the disease), there is a greater chance that their children are going to inherit the mutations from both parents and display the disease. This is especially important to consider in consanguineous marriage, where the chance of both parents having the same mutation and passing it is greater.