IDS and mucopolysaccharidosis type 2: Among the 21 IDS gene variants, only five have been reported previously for clinically diagnosed MPS II, all of which were reported in the literature rather than from newborn screening programs for MPS II, namely c.1400C > T, p.P467L [32,33], c.1007–1666_c.1180 + 2113 delinsTT [34,35], IDS inversion [18,36], c.851C > T, p.P284L [37], and c.301C > T, p.R101C [38].