Expanding the phenotypic spectrum of Xq28 duplication involving MECP2: a familial case report (opens in new tab)

X-linked intellectual disability (XLID) is a well-recognized group of neurodevelopmental disorders, with pathogenic variants in X-chromosomal genes accounting for approximately 16% of intellectual disability cases in males. Clinical expression in females is variable and depends on patterns of X-chromosome inactivation. We describe three affected individuals from a single family with XLID caused by a confirmed duplication of the Xq28 region, including the genes SLC6A8, L1CAM, MECP2, TKTL1, FLN...