Table 4.
DC genetic subtypes
| DC Subtype | Approximate % of patients with DC | Chromosome location | Gene product | Exons |
|---|---|---|---|---|
| X-linked recessive | 25 | Xq28 | DKC1 (dyskerin) 15 | |
| Autosomal dominant | 12 | 14q12 | TIN2 | 6 |
| 5 | 3q26.2 | TERC* | 1 | |
| 3 | 5p15.33 | TERT* | 16 | |
| <1 | 4q32.2 | NAF1* | 13 | |
| <1 | 12q24.31 | ZCCHC8* | 17 | |
| <1 | 5q35.1 | NPM1 | 13 | |
| <1 | 1q32.1 | MDM4 | 13 | |
| Autosomal recessive | 2 | 16q21 | USB1 | 9 |
| 2 | 20q13.3 | RTEL1* | 35 | |
| 1 | 16p13.12 | PARN* | 27 | |
| <1 | 15q14 | NOP10 | 2 | |
| <1 | 5p15.33 | TERT* | 16 | |
| <1 | 5q35.3 | NHP2 | 4 | |
| <1 | 17p13.1 | WRAP5313 | ||
| <1 | 17p13.1 | CTC1 | 23 | |
| <1 | 16q22.1 | ACD/TPP1 | 13 | |
| Uncharacterized | >30 | ? | ? | ? |
The major subtypes of DC are associated with variants in DKC1, TINF2, TERC, and TERT.
*
Heterozygous variants in these genes have been associated with pulmonary disease in late adulthood. Most of the DC genes encode products that have a principal role in telomere maintenance; however, this is not the case for USB1 and NPM1. Variants in some other genes (GRHL2, DNAJC3, RECQL4, and LIG4) can produce features that overlap with DC.