Dyskeratosis congenita. Haematologic, cytogenetic, and dermatologic studies

In a family of 5 boys and 6 girls, 3 brothers have clinical dyskeratosis congenita. Teeth from 2 of the patients were taurodent , and mineral density of the enamel was significantly different from normal. The haematopoietic marrow was hypocellular and there was striking prominence of plasma cells having normal morphology; no granulomata were demonstrated. The decreased erythroid precursors in the marrow correlated with quantitatively reduced erythropoiesis demonstrated on ferrokinetic studies. Recurrent infections occurred but could not be related to neutropenia, and granulocytes and monocytes retained normal function. No abnormality was demonstrated in humoral or cellular immune mechanisms. While superficially similar, dyskeratosis congenita and Fanconi's anaemia are genetically distinct, being X-linked in the former and inherited as an autosomal recessive in the latter.