Alström syndrome is a rare multisystemic disease due to pathogenic variants in the ALMS1 gene. It is characterised by early onset cone-rod dystrophy (usually in childhood), progressive sensorineural hearing loss, childhood-onset obesity and metabolic disorder, and dilated cardiomyopathy. Other features may be present as well.

Cone or cone-rod dystrophies encompasses a group of progressive inherited retinal dystrophies characterised by predominant impairment of cone-mediated vision. This may be accompanied by rod dysfunction. It can be an isolated phenotype or associated with systemic features (Alstrom syndrome and Bardet-Biedl syndrome).

Cone dystrophy and cone-rod dystrophy describe a group of inherited retinal disease that primarily affects of the normal cone photoreceptors of the retina. This results in reduced central vision and difficulty in recognising colours.

Stargardt disease is the most common form of inherited macular degeneration. It is caused by mutations in the ABCA4 gene, resulting in progressive vision.