[Central hypomyelination, hypogonadotrophic hypogonadism and hypodontia: a new leukodystrophy]

To report one patient with slowly progressive encephalopathy, ataxia, central hypomyelination, hypodontia and hypogonadotropic hypogonadism, the 4H syndrome. This clinical picture has been described recently and there are only four patients reported previously.

A girl with a previously normal early psychomotor development, presented a slowly progressive deterioration since 15 months of age. Now, she is 14 years old, and has a severe cerebellar ataxia, with tremor and dysmetria. She can't neither walk nor remain standing alone. She has lost the sphincter control and has an immature expressive language. She has no puberal development and definitive hypodontia of upper central incisors. The brain magnetic resonance imaging shows a diffuse hypomyelination, that is confirmed with diffusion and spectroscopy studies.

The hypomyelinating leukoencephalopathies are disorders with abnormally low amount of myelin. The diagnosis is difficult in most of the patients. The hypomyelinating leukoencephalopathies include classic disorders and new leukoencephalopathies, described in the past few years.