Dyskeratosis congenita.

Dyskeratosis congenita is an inherited disorder that usually presents in males, consisting of the triad of leukoplakia of the mucous membranes, nail dystrophy and skin pigmentation. Whilst most cases are X-linked, autosomal dominant and recessive forms have been reported. The significance of the condition lies in premature mortality arising from either bone marrow failure or malignant change within the areas of leukoplakia. Various mucocutaneous and non-mucocutaneous manifestations have been reported. The syndrome arises from an inherited defect within the DKC1 gene that codes for the protein dyskerin in the X-linked recessive form of the disorder, whereas mutations in the RNA component of telomerase (TERC) result in the autosomal dominant form of the condition. The identification of a white patch within the mouth of a child in the absence of any other obvious cause should arouse suspicion of this rare condition. Greater understanding of the molecular biology surrounding this syndrome should lead to improvements in diagnosis, monitoring of disease progression and therapy.