Clinical manifestations in female carriers of mucopolysaccharidosis type II: a spanish cross-sectional study

Background Mucopolysaccharidosis type II (MPS II) is an inherited X-linked disease associated with a deficiency in the enzyme iduronate 2-sulfatase due to iduronate 2-sulfatase gene (IDS) mutations. Recent studies in MPS II carriers did not find clinical involvement, but these were mainly performed by anamnesis and patients’ self-reported description of signs and symptoms. So although it is rare in heterozygous carriers, investigations in other types of inherited X-linked disorders suggest that some clinical manifestations may be a possibility. The aim of this study was to evaluate the clinical pattern in female carriers of MPS II and to determine whether clinical symptoms were associated with the X-chromosome inactivation (XCI) pattern and age.