Alström syndrome

Alström syndrome is a very rare, multi-system, autosomal recessive genetic disorder characterized by type 2 diabetes, cone-rod dystrophy leading to blindness, sensorineural hearing loss and cardiomyopathy. Endocrine problems such as hypergonadotrophic hypogonadism and hypothyroidism are common, as is acanthosis nigricans from hyperinsulinemia. It is caused by variants in the ALMS1 gene, which is involved in forming cellular cilia, so the syndrome counts as a ciliopathy. It is sometimes confused with Bardet-Biedl syndrome, which involves multiple genes and includes polydactyly. There is no cure or specific therapy, and treatment targets individual symptoms. Prognosis varies, and affected people rarely live beyond 50. Prevalence is cited as about 1 in 1,000,000, probably an underestimate.