[Two cases of X-linked ichthyosis associated with myopathies]

X-linked ichthyosis is an inborn error of metabolism due to the deficiency of steroid sulfatase. We reported two cases of the patients associated with myopathies, which are Duchenne muscular dystrophy (DMD) and myotonic dystrophy (MyD), respectively. In addition to DMD and MyD, they showed corneal opacities, lack of steroid-sulfatase activities in peripheral leukocytes and massive accumulation of cholesterol sulfate in plasma. Such cases were not reported, previously. Assay of steroid sulfatase and cholesterol sulfate in the patients having ichthyosis is important to elucidate the wide clinical spectrum of steroid sulfatase deficiency.