_:vb50942943 . _:vb50942943 . _:vb50942943 "url:https://www.ncbi.nlm.nih.gov/pubmed/9425888"^^ . _:vb50942943 . _:vb50942943 . _:vb50942943 . _:vb50942943 "A retinitis pigmentosa that has_material_basis_in mutation in the ABCA4 gene on chromosome 1p22."^^ .