The inheritance of DC is genetically heterogeneous, including autosomal dominant inheritance (TERT, TERC, TINF2, TPP1 or RTEL1), autosomal recessive inheritance (TERT, WRAP53, NOP10, NHP2, CTC1, PARN or RTEL1), and X-linked inheritance (DKC1) [19, 20]. The gene discussed is RTEL1; the disease is dyskeratosis congenita.