A 16-year-old male patient had a syndrome that included growth retardation, mental retardation, hair shaft abnormalities, neurosensory hearing loss, contractures of the fifth fingers, ultraviolet B (UVB) photosensitivity, small testicular size, and elevated levels of follicle-stimulating hormone. Reduced hair sulfur content and a characteristic pattern of light and dark birefringent bands, seen when hairs were viewed with polarization microscopy, were typical of the low-sulfur hair syndrome. UVB photosensitivity and testicular failure have not previously been identified as components of this syndrome.