A case report of a patient with mucopolysaccharidosis type II

Mucopolysaccharidosis type II (MPS II) or Hunter syndrome is an inborn error of metabolism due to lysosomal accumulation, with a recessive inheritance pattern linked to the X chromosome. It is caused by a deficiency in the activity of the lysosomal enzyme iduronate-2-sulfatase encoded by the IDS gene. Iduronate-2-sulphatase enzyme activity in plasma was measured and the IDS gene was analysed in genomic DNA by automated direct sequencing. Enzyme activity was 1.2 μmol/l/h (reference value: >2 μmol/l/h), while the molecular analysis detected the mutation c.1403G>A (p.R468Q), confirming the diagnosis of MPS II. In conclusion, since here in Mexico there are few groups dedicated to this family of diseases, we must emphasise the need to keep up to date and create expert teams of doctors and scientists specialised in inborn errors of metabolism.