Mucopolysaccharidosis VI (Maroteaux‐Lamy Syndrome) with Hearing Impairment and Pupillary Membrane Remnants

A Japanese boy aged 13 months was referred to us because thickened ribs had been observed on a chest X-ray taken during a respiratory infection. Mucopolysaccharidosis type VI (MPS VI) was diagnosed based on urinary glycosaminoglycan analysis and low activity of arylsulfatase B in peripheral leukocytes. He had mild pupillary membrane remnants, but no corneal opacities. The auditory brainstem response revealed moderate hearing impairment, which may have caused his subnormal DQ score of 85 at the age of 19 months. Although MPS VI is characterized by normal intellectual development with normal hearing in early infancy, it is important to examine for hearing loss, especially when an infant with this disease shows developmental delay.