Sexual precocity in hypomelanosis of Ito: Mosaicism-associated case report and literature review

Background Hypomelanosis of Ito (HI), a neurocutaneous disorder characterized by hypopigmented skin lesions along Blaschko's line with multiple accompanying diseases, may occasionally present with sexual precocity. Methods We reviewed cases of HI with sexual precocity reported in the literature and focused on collecting information on other associated organ abnormalities, chromosomal karyotype, and type of sexual precocity. We also present our own case report. Results Five children with sexual precocity in HI were studied. All patients were full-term females without significant family history. Their ages ranged from three years to 11years. Skin lesions involved the trunk and limbs. Developmental delay was present in all patients. Central nervous system involvement was found in four patients. Craniofacial abnormalities were present in four patients. Eye involvement was present in two patients. Limb abnormalities (brachydactyly and clinodactyly) were present in two patients. Skeletal organ involvement was present in three patients. Other skin lesions were present in three patients. Dental abnormalities occurred in one patient. Of the five patients, four demonstrated a peripheral type of sexual precocity, and one presented with central type sexual precocity. Vaginal bleeding was present in two patients. Chromosomal karyotype abnormalities were found in two patients, and mosaicism was present in one of these. Conclusions Hypomelanosis of Ito is a syndrome characterized by cutaneous signs frequently associated with nervous, ocular, and musculoskeletal system abnormalities. Although it is rarely reported in conjunction with HI, physicians should recognize sexual precocity as a possible associated symptom.