GAPO syndrome was described in 12 patients from 7 families. Constant manifestations include dwarfism, alopecia, pseudoanodontia, and a peculiar, "geriatric" facial appearance. We describe the autopsy findings and all available clinical data on one deceased patient and his living affected sister, previously reported as short abstracts (Epps et al.: Cienc Cult 29(Suppl):740, 1977; Wajntal et al.: Cienc Cult 34(Suppl):705, 1982). Both had the characteristic anomalies of this syndrome but optic atrophy was absent; instead, they had glaucoma and keratoconus; hypogonadism was present in both patients. Biopsy and autopsy findings show that the GAPO syndrome is a dyshistogenetic sequence due to accumulation of extracellular material and thus should be called GAPO dysplasia. We suggest that the basic defect in this autosomal recessive disorder is possibly related to a lack of breakdown of the extracellular components, perhaps due to an enzyme deficiency involved in the metabolism of extracellular matrix.