[Hypomelanosis of Ito. A possibly under-diagnosed heterogeneous neurocutaneous syndrome]

Hypomelanosis of Ito (HI) or incontinentia pigmenti achromians is a multisystemic neurocutaneous disorder that is associated to neurological complications in a high percentage of patients.

The purpose of this study is to review the most significant features in a series of 14 patients with HI.

We conducted a retrospective study in which the following data were analysed: age, sex, familial and personal history, clinical features and complementary explorations that were carried out. We report the cases of nine females and five males aged between 4 months and 14 years.

All the patients presented neurological anomalies, including psychomotor or mental retardation in 11 (associated to autistic behaviour in two of them), neuroradiological anomalies in seven, microcephalus in three and epileptic seizures in two. Other significant complications were musculoskeletal and ocular anomalies (each of which were present in nine patients), dental disorders in six, coarse facies and dysmorphic ears in four patients, hypoacusis in five and congenital heart disease in two. The following were also observed, but as isolated events: choanal atresia, cleft palate, segmental dilatation of the colon, cryptorchidism, inguinal hernia, low height, vesicoureteral reflux and premature pubarche.

There is no biological marker that identifies HI and a number of clinical forms only appear in the skin in a very mild form, which means they sometimes going unnoticed or are not considered to be important enough to establish a diagnosis. This entity may, therefore, be more frequent than we think and its prevalence is perhaps underestimated.