[GAPO syndrome].

INTRODUCTION: The GAPO syndrome is a rare but distinct genetic disorder. GAPO is an acronym for the manifestation of Growth retardation, Alopecia, Pseudoanodontia and Optic atrophy. The syndrome was first reported in 1947; to date, 24 cases have been reported. We report the first Tunisian case. OBSERVATION: We studied a 12 year-old boy with GAPO syndrome which was associated with peculiar facial appearance, umbilical hernia, hemangiomatous plaques of the neck, depigmented maculae arranged in a splashed pattern located in the trunk and the right upper limb. He had a pulsated mass in the right mastoid area and a bruit was audible, he had a second flaccid mass of the vertex. These tumefactions correspond to very developed commissure veins. DISCUSSION: In addition to the classical manifestations of the GAPO syndrome, the patients have a strikingly characteristic facial appearance and may also have umbilical hernia, skin redundance and prominent dilatation of scalp veins. Our case had depigmented maculae suggestive of incontinentia pigmenti achromians. This has never been reported previously. The pathogenesis of this syndrome is unknown and inheritance is considered to be autosomal recessive.