Deafness is evident in the first years of life.
The severity stabilizes by puberty. Abnormalities of hair (alopecia, or
coarse, dry, lusterless, fragile hair) are present and mainly of cosmetic
concern. Microscopic examination of the hair shaft shows flattening at
irregular intervals and a 180-degree twisting around its axis. Diagnosis is
confirmed by optical and scanning electron microscopy. Mental retardation or hypogonadism in some patients.