X-linked mental retardation has been traditionally divided into syndromic ( S-XLMR ) and non-syndromic forms ( NS-XLMR ) , although the borderlines between these phenotypes begin to vanish and mutations in a single gene , for example PQBP1 , can cause S-XLMR as well as NS-XLMR .
B-DiseaseOrPhenotypicFeature I-DiseaseOrPhenotypicFeature I-DiseaseOrPhenotypicFeature O O O O O O O I-DiseaseOrPhenotypicFeature O O O O O I-DiseaseOrPhenotypicFeature O O O O O O O O O O O O O O O O O O O O B-GeneOrGeneProduct O O O I-DiseaseOrPhenotypicFeature O O O I-DiseaseOrPhenotypicFeature O