Hypomelanosis of Ito associated with precocious puberty.

Hypomelanosis of Ito has been associated with precocious puberty in two cases. This study reports a third case involving a female with hypomelanosis of Ito including severe mental retardation and seizure disorder with autonomic symptoms (gastroesophageal reflux and asthma). At age 5 she developed vaginal discharge, thelarche, and adrenarche. Soon after, she died of pneumonia stemming from her neurologic deficits. A postmortem examination revealed normal gonads and endocrine organs. The breasts and vulva were prematurely developed. Central nervous system findings included megalencephaly, neuronal eosinophilic inclusions, leptomeningeal neuroglial heterotopias, and cortical dysplasia. Both previously reported cases of hypomelanosis of Ito associated with precocious puberty had abnormal gonads and responded to cyproterone acetate therapy, indicating a peripheral mechanism of precocious puberty (gonadotrophin-independent). The current case, which was autopsied, lacks significant gonadal pathology, and has extensive neurologic involvement that suggests that a central mechanism of precocious puberty (gonadotrophin-dependent) can also be associated with hypomelanosis of Ito.