Functional overlap of DC genes involved in telomere maintenance and ribosome biogenesis. Proteins mutated in DC are indicated by named capsules and affect molecular functions, such as telomere replication (RTEL1), telomere protection (TIN2, ACD), telomerase (TERC, TERT, and DKC1), and telomerase maturation and stability (ZCCHC8, NAF1, PARN, DKC1, NOP10, and NHP2). Pseudouridylation of TERC and ribosomal RNA (rRNA) is performed by DKC1. The deadenylation function of PARN also regulates the maturation and processing of both TERC and rRNA. Recently, variants in NPM1 that regulate 2'O rRNA methylation have been reported in patients with DC. USB1 is an outlier, being involved in U6 spliceosomal RNA processing. Dashed arrows link different proteins to specific functions in which they are involved.