Incidence of CDKN2A deletions by sex, age, white cell count, and cytogenetic subgroup in childhood acute lymphoblastic leukemia (ALL)
| Subgroup . | BCP-ALL cohort . | T-ALL cohort . | |||||
|---|---|---|---|---|---|---|---|
| Total . | Deletion, n (%) . | Biallelic deletion, n (% of deleted cases) . | . | Total . | Deletion, n (%) . | Biallelic deletion, n (% of deleted cases) . | |
| Total | 864 | 180 (21) | 78 (43) | 266 | 134 (50) | 83 (62) | |
| Sex | |||||||
| Male | 473 | 96 (20) | 43 (45) | 191 | 96 (50) | 63 (66) | |
| Female | 391 | 84 (21) | 35 (42) | 75 | 38 (51) | 20 (53) | |
| Age groups | |||||||
| < 10 y | 679 | 129 (19)g | 53 (41) | 141 | 81 (57)g | 47 (58) | |
| 10+ y | 185 | 51 (28)g | 25 (49) | 125 | 53 (42)g | 36 (68) | |
| White cell counta | |||||||
| < 50 × 109/L | 636 | 109 (17)h | 50 (46) | 82 | 37 (45) | 23 (62) | |
| > 50 × 109/L | 154 | 55 (36)h | 19 (35) | 172 | 88 (51) | 55 (63) | |
| Cytogenetic subgroupsb | Cytogenetic subgroupsb | ||||||
| High hyperdiploidyc | 279 | 30 (11)h | 14 (47) | TAL1 rearrangementsi | 49 | 21 (43) | 12 (57) |
| ETV6-RUNX1 | 218 | 33 (15)g | 15 (45) | TLX3 rearrangementsj | 41 | 31 (76)h | 18 (58) |
| t(1;19)(q23;p13) | 25 | 10 (40)g | 2 (20) | LMO2 rearrangementsk | 23 | 9 (39) | 6 (67) |
| MLL translocationsd | 22 | 2 (9) | 1 (50) | MLL translocationsd | 11 | 2 (18) | 1 (50) |
| t(9;22)(q34;q11) | 19 | 11 (58)h | 1 (9)g | TLX1 abnormalitiesl | 9 | 8 (89)g | 4 (50) |
| iAMP21e | 19 | 5 (26) | 3 (60) | AF10-CALM | 9 | 4 (44) | 1 (25) |
| Normal karyotypef | 52 | 6 (12) | 6 (100)h | Normal karyotypef | 55 | 23 (42) | 18 (78) |
| Subgroup . | BCP-ALL cohort . | T-ALL cohort . | |||||
|---|---|---|---|---|---|---|---|
| Total . | Deletion, n (%) . | Biallelic deletion, n (% of deleted cases) . | . | Total . | Deletion, n (%) . | Biallelic deletion, n (% of deleted cases) . | |
| Total | 864 | 180 (21) | 78 (43) | 266 | 134 (50) | 83 (62) | |
| Sex | |||||||
| Male | 473 | 96 (20) | 43 (45) | 191 | 96 (50) | 63 (66) | |
| Female | 391 | 84 (21) | 35 (42) | 75 | 38 (51) | 20 (53) | |
| Age groups | |||||||
| < 10 y | 679 | 129 (19)g | 53 (41) | 141 | 81 (57)g | 47 (58) | |
| 10+ y | 185 | 51 (28)g | 25 (49) | 125 | 53 (42)g | 36 (68) | |
| White cell counta | |||||||
| < 50 × 109/L | 636 | 109 (17)h | 50 (46) | 82 | 37 (45) | 23 (62) | |
| > 50 × 109/L | 154 | 55 (36)h | 19 (35) | 172 | 88 (51) | 55 (63) | |
| Cytogenetic subgroupsb | Cytogenetic subgroupsb | ||||||
| High hyperdiploidyc | 279 | 30 (11)h | 14 (47) | TAL1 rearrangementsi | 49 | 21 (43) | 12 (57) |
| ETV6-RUNX1 | 218 | 33 (15)g | 15 (45) | TLX3 rearrangementsj | 41 | 31 (76)h | 18 (58) |
| t(1;19)(q23;p13) | 25 | 10 (40)g | 2 (20) | LMO2 rearrangementsk | 23 | 9 (39) | 6 (67) |
| MLL translocationsd | 22 | 2 (9) | 1 (50) | MLL translocationsd | 11 | 2 (18) | 1 (50) |
| t(9;22)(q34;q11) | 19 | 11 (58)h | 1 (9)g | TLX1 abnormalitiesl | 9 | 8 (89)g | 4 (50) |
| iAMP21e | 19 | 5 (26) | 3 (60) | AF10-CALM | 9 | 4 (44) | 1 (25) |
| Normal karyotypef | 52 | 6 (12) | 6 (100)h | Normal karyotypef | 55 | 23 (42) | 18 (78) |
Data are missing for 86 patients.
Patients with each specific abnormality were compared with either all other patients with successful cytogenetics or those who tested negative for that particular abnormality by FISH, as appropriate.
Karyotypes with 51 to 65 chromosomes.
Patients positive by FISH or with an established translocation by G-banded analysis.
Intrachromosomal amplification of chromosome 21.
A normal karyotype was defined as the presence of 20 or more normal metaphases and the absence of any cytogenetically visible abnormality or any abnormality detected by FISH.
P < .05.
P < .01.
Involvement of TAL1 was confirmed by FISH in all cases. Group comprised SIL-TAL1 (n = 43), t(1;14)(p32;q11)/TAL1-TRA@/TRD@ (n = 5), and t(1;14)(p32;q32)/TAL1-IGH@ (n = 1).
Involvement of TLX3 (HOX11L2) was confirmed by FISH in all cases. In 33 cases, BCL11B was also confirmed to be involved, ie, t(5;14)(q35;q32).
Involvement of LMO2 was confirmed by FISH in all cases and the partner gene was identified in 20 cases: t(11;14)(p13;q11)/LMO2-TRA@/TRD@ (n = 15), t(7;11)(q34;p13)/LMO2-TRB@ (n = 3), t(7;11)(p15;p13)/LMO2-TRG@ (n = 1), and t(11;14)(p13;q32)/LMO2-BCL11B (n = 1).
Involvement of TLX1 (HOX11) was confirmed by FISH in all cases and the partner gene was identified in 7 cases: t(10;14)(q24;q11)/TLX1-TRA@/TRD@ (n = 4) and t(7;10)(q36;q24)/TLX1-TRB@ (n = 3).