Characteristics of study participants
| Patients with DC | Unaffected relatives | Patients versus relatives p-value | ||||||
| All | XLR, AR, TINF2# | AD non-TINF2# | p-value | All | Carriers of RTEL1, TERT or PARN | All others | ||
| Participants | 43 | 25 | 14 | 67 | 14 | 53 | ||
| Age at diagnosis years | 13 (1–65) | 11 (1–43) | 32 (12–65) | <0.0001 | ||||
| Age at study years | 21 (6–69) | 18 (6–42) | 35 (12–69) | 0.002 | 46 (10–60) | 46 (10–60) | 36 (7–64) | 0.0001 |
| Male/female | 31/12 | 21/4 | 7/7 | 0.03 | 25/42 | 6/8 | 19/34 | 0.001 |
| Smoker | 7 (15%) | 3 | 4 | 0.2 | 10 (15%) | 3 (21%) | 7 (13%) | 0.8 |
| Ethnicity | ||||||||
| Caucasian | 40 | 24 | 12 | 63 | 14 | 49 | 0.7 | |
| African | 2 | 1 | 1 | 0 | 0 | 0 | ||
| Hispanic | 0 | 0 | 0 | 1 | 0 | 1 | ||
| Asian | 1 | 0 | 1 | 3 | 0 | 3 | ||
| Microcephaly | 11 | 11 | 0 | 0.003 | 0 | 0 | 0 | |
| HH/RS | 8 | 8 | 0 | 0.03 | 0 | 0 | 0 | |
| DC triad features¶ | ||||||||
| 0–1 | 20 | 8 | 11 | 0.008 | 63 | 14 | 53 | |
| ≥2 | 23 | 17 | 3 | 0 | 0 | 0 | ||
| Bone marrow failure+ | ||||||||
| None | 12 | 7 | 5 | 0.2 | 0 | 0 | 0 | |
| Moderate | 13 | 4 | 5 | |||||
| Severe | 18 | 14 | 4 | |||||
| Telomere length Z-score | −3.9 | −4.5 (−1.3– −6.7) | −3.1 (−1.1– −5.5) | 0.0007 | −0.9 (−1.8– −4.2) | −1.9 (−0.3– −1.9) | −0.7 (−0.7– −4.2) | <10-9 |
| DC gene (inheritance) | ||||||||
| DKC1 (XLR) | 7 | 7 | 0 | 7 | 0 | 7 | ||
| RTEL1 (AR or AD) | 7 | 6 | 1 | 8 | 8 | 0 | ||
| PARN (AR) | 3 | 3 | 0 | 5 | 5 | 0 | ||
| WRAP53 (AR) | 0 | 0 | 0 | 3 | 0 | 3 | ||
| ACD (AR) | 0 | 0 | 0 | 2 | 0 | 2 | ||
| TERT (AR or AD) | 6 | 1 | 5 | 1 | 1 | 0 | ||
| TINF2 (AD) | 8 | 8 | 0 | 0 | 0 | 0 | ||
| TERC (AD) | 8 | 0 | 8 | 0 | 0 | 0 | ||
| Unknown | 4 | 0 | 0 | 15 | 0 | 15 | ||
| Negative | 0 | 26 | 0 | 26 | ||||
Data are presented as median (range) unless otherwise stated. DC: dyskeratosis congenita; XLR: X-linked recessive; AR: autosomal recessive; AD: autosomal dominant; HH: Hoyeraal–Hreidarsson syndrome; RS: Revesz syndrome. #: the number of patients with XLR/AR/TINF2 and AD non-TINF2 do not add up to the total of 43 because the causative gene was not identified in four patients; ¶: oral leukoplakia, dysplastic nails and abnormal skin pigmentation; +: “moderate” was defined as single or multilineage cytopenia not on treatment, and “severe” was cytopenia needing treatment. Significant p-values (<0.05) are in bold.