DKC1 and dyskeratosis congenita: DKC1, which encodes a nucleolar protein called DKC1 (dyskerin)1, is the first gene identified to play a role in dyskeratosis congenita (DC), which is a rare inherited disease that is estimated to affect approximately one person per million people and is mainly characterized by the triad of abnormal skin pigmentation, oral leucoplakia, and nail dystrophy2.