Table 1.
Characteristics of study participants
| Entire cohort, n | Clinic cohort, n | Field cohort, n | |
|---|---|---|---|
| Number of families | 124 | 50 | 74* |
| Number of individuals | 231 | 91 | 140* |
| Male:female | 144:87 | 57:34 | 87:53 |
| Self-reported race/ethnicity | |||
| White | 170 | 83 | 87 |
| Asian | 6 | 2 | 4 |
| Black | 1 | 1 | 0 |
| Native American | 1 | 1 | 0 |
| Mixed | 9 | 3 | 6 |
| Unknown | 44 | 1 | 43 |
| Diagnosis categories | |||
| DC/TBD | 199 | 79 | 120 |
| HH | 23† | 10 | 13 |
| Revesz syndrome | 6‡ | 2 | 4 |
| Coats plus | 3§ | 0 | 3 |
| Median age at diagnosis in years (range)ǁ | 19.4 (0-71.6) | 22.3 (0-69.4) | 18.4 (0-71.6) |
| Patients diagnosed <18 y of age | 96 | 41 | 55 |
| Patients diagnosed ≥18 y of age | 111 | 50 | 61 |
| Median follow-up since diagnosis (range)ǁ,# | 5.2 (0-36.7) | 7.6 (0-30.2) | 2.7 (0-36.7) |
| Median age at follow-up in years (range) | 29.6 (1.3-82.2) | 29.2 (2.2-79.5) | 29.8 (1.3-82.2) |
| Number deceased at last follow-up | 97 | 32 | 65 |
| Gene known ¶ | 200 | 84 | 116 |
| TERT (AR,AD) | 49 (2,47) | 14 (2,12) | 35 (0,35) |
| RTEL1 (AR,AD)# | 44 (15,29) | 24 (9,15) | 20 (6,14) |
| DKC1 (XLR) | 32 | 11 | 21 |
| TERC (AD) | 30 | 10 | 20 |
| TINF2 (AD) | 25 | 14 | 11 |
| PARN (AR,AD) | 8 (4,4) | 6 (3,3) | 2 (1,1) |
| CTC1 (AR) | 6 | 0 | 6 |
| WRAP53 (AR) | 3 | 2 | 1 |
| ACD (AR,AD) | 3 (1,2) | 3 (1,2) | 0 |
| Gene unknown | 31 | 7 | 24 |
| Inheritance pattern | |||
| AD | 112 | 42 | 70 |
| AR/XLR | 63 | 28 | 35 |
| TINF2 (de novo,AD) | 25 (13,12) | 14 (7,7) | 11 (6,5) |
Follow-up was defined as last contact with study center by treating physician, participant, or family through questionnaire, clinical report, e-mail, or phone call.
AD, autosomal dominant; ACD, ACD shelterin complex subunit and telomerase recruitment factor; AR, autosomal recessive; CTC1, CST telomere replication complex component 1; DC, dyskeratosis congenita; DKC1, dyskerin; HH, Hoyeraal-Hreidarsson syndrome; RTEL1, regulator of telomere elongation; TBD, telomere biology disorders; TERC, telomerase RNA component; TERT, telomerase reverse transcriptase; TINF2, TERF1 interacting nuclear factor 2; PARN, poly(A)-specific ribonuclease; WRAP53, WD repeat containing antisense to TP53; XLR, X-linked recessive.
32 field cohort participants were members of clinic cohort families.
2 AD, 18 AR/XLR, 3 unknown.
3 TINF2, 1 AR/XLR, 2 unknown.
3 AR/XLR.
The diagnosis was established postmortem for 24 patients: they were not included in the calculation of age at diagnosis or follow-up since diagnosis.
Includes 25 individuals with inferred genotype based on family history and inheritance pattern of genotype.
The follow-up period since diagnosis was significantly lower in the field vs the clinic cohort. There was a significant difference in the distribution of RTEL1 affected in the clinic vs field cohort.