Variants in the ABCA4 gene are associated with a spectrum of inherited retinal diseases (IRDs), most prominently with autosomal recessive (ar) Stargardt disease (STGD1) and ar cone-rod dystrophy.
Based on these data we estimate a prevalence of 31% for ABCA4 mutations in arCD and arCRD, supporting the concept that the ABCA4 gene is a major locus for various types of degenerative retinal diseases with abnormalities in cone or both cone and rod function.
Patients with Stargardt disease or cone-rod dystrophy and known or suspected disease-causing mutations in the ABCA4 gene were included.All patients had foveal fixation.
We found a new pathologic ATP-binding cassette transporter (ABCA4) splice-site mutation, c.3523-2A>T and the previously reported c.5327C>T (p.P1776L) missense mutation in the arCRD patients.
The new 6730-16del44 deletion is the first de novo mutation associated with cone-rod dystrophy and may contribute to a better understanding of the role of ABCA4 mutations in macular dystrophies.
Our findings confirm that a substantial percentage of patients with autosomal recessive cone-rod dystrophy are likely to harbor a mutation in the ABCA4 gene as the cause of their disease.
Mutations in ABCR (ABCA4) have been reported to cause a spectrum of autosomal recessively inherited retinopathies, including Stargardt disease (STGD), cone-rod dystrophy and retinitis pigmentosa.