Purpose: Among the 500 ABCA4 mutations identified so far in the retina-specific ABC transporter (ABCA4) gene, only 20 have been described in patients with autosomal recessive retinitis pigmentosa (arRP). In this study the gene was screened for mutations in a cohort of 25 patients of Spanish origin, to further assess ABCA4 involvement in retinal dystrophies.
Methods: The 50 exons of the ABCA4 gene have been analyzed through denaturing high performance liquid chromatography (DHPLC) and direct sequencing of samples displaying altered elution profiles.
Results: Four new and five known mutations were identified in our patients; except for one new deletion detected in a patient with Stargardt disease, all the remaining variations are single nucleotide substitutions resulting in missense mutations.
Conclusions: The results further underline the genetic heterogeneity of retinal disorders, suggesting that more than one gene could differentially contribute to at least some forms of retinal degeneration. Finding a high proportion of novel mutations merits the use of scanning methodologies to analyze the whole coding region of the ABCA4 gene.