Clinical characteristics
| . | Twin 1 (Tw1) . | Twin 2 (Tw2) . |
|---|---|---|
| Diagnosis | BCP-ALL | BCP-ALL |
| Age at diagnosis | 3y 4m | 3y 10m |
| Full blood count at diagnosis (peripheral blood) | ||
| Hb (g/L) | 41 | 69 |
| WBC (×109/L) | 2.8 | 2.8 |
| Platelets (×109/L) | 128 | 163 |
| Immunophenotype (bone marrow) | CD45dim, CD19+, CD10++, CD20−, TdT+, CD22+, CD cyt79a+, CD38+, HLADR+, CD123dim, CD58+, CD66c−, cytIgM−, no myeloid markers, subpopulation (36%) CD34+ | CD45dim/neg, CD19+, CD10++, CD20−, Tdt+, CD22+, CD cyt79a+, CD38+, HLADR+, CD123dim/neg, CD58+, CD66c−, cytIgM−, no myeloid markers, CD34hetero/+, no T-cell markers, CD99++ |
| Blast count at diagnosis (bone marrow) | 69% | 74% |
| CNS engagement of leukemia | No | No |
| Cytogenetics (bone marrow at diagnosis) | ||
| Karyotyping with G-banding | 46,XX,t(11;12)(q21;p13)[6]/46,XX[19] | 46,XX,t(11;12)(q23;p13)[5]/47,XX,sl, t(1;12)(p13;p13),+der(1)t(1;12)(p13;p13)[9]/46,XX[3] |
| FISH | nuc ish(ETV6x2,RUNX1x3)(ETV6 con RUNX1x1)[145/206],(ETV6x1,RUNX1x3)(ETV6 con RUNX1x1)[12/206] | nuc ish(ETV6x2,RUNX1x3)(ETV6 con RUNX1x1)[98/222],(ETV6x1,RUNX1x3)(ETV6 con RUNX1x1)[98/222] |
| ArrayCGH | No detectable copy number changes | No additional finding |
| Interpretation | Main clone with t(11;12) and ETV6-RUNX1 (70%), subclone with additional delETV6 (6%) | Main clone with t(11;12) and ETV6-RUNX1 (88%), subclone with additional delETV6 and t(1;12) with extra der(1)t(1;12) (44%) |
| Image cytometric DNA analysis (ICDA) | Diploid (DNA index: 0.5, S-phase 8%) | Diploid (DNA index: 1, S-phase 8%) |
| Treatment protocol | NOPHO-ALL 2008 standard risk arm | NOPHO-ALL 2008 standard risk arm |
| Stem cell transplantation | No | No |
| Minimal residual disease | ||
| Day 15 | <0.1% | <0.1% |
| Day 29 | <0.1% | <0.01% |
| Day 79 | <0.01% | <0.01% |
| Complications and treatment related toxicities | Gastroenteral chlostridium difficile infection. Bilateral purulent heamophilus influenzae conjunctivitis. HSV keratitis. Severe varicella infection with concurrent hepatitis of unknown etiology | Vincristine neuropathy with remaining muscular weakness in lower limbs. Acute ITP after end of intense treatment phase, spontaneous regression after steroid treatment |
| Adjustments to treatment protocol | Dose reduction of high-dose methotrexate due to high top-concentrations and delayed excretion with renal toxicity | Dose reduction of Vincristine due to toxicity (peripheral neuropathy) |
| Relapse | No. Currently in complete remission 5.5 y after diagnosis | No. Currently in complete remission 5 y after diagnosis |
| Current growth and developmental parameters | ||
| Height | −1.64 SD | −1.72 SD |
| Weight | −0.94 SD | −1.3 SD |
| Head size | Not available | Not available |
| Psychomotor development | Normal | Normal |
| . | Twin 1 (Tw1) . | Twin 2 (Tw2) . |
|---|---|---|
| Diagnosis | BCP-ALL | BCP-ALL |
| Age at diagnosis | 3y 4m | 3y 10m |
| Full blood count at diagnosis (peripheral blood) | ||
| Hb (g/L) | 41 | 69 |
| WBC (×109/L) | 2.8 | 2.8 |
| Platelets (×109/L) | 128 | 163 |
| Immunophenotype (bone marrow) | CD45dim, CD19+, CD10++, CD20−, TdT+, CD22+, CD cyt79a+, CD38+, HLADR+, CD123dim, CD58+, CD66c−, cytIgM−, no myeloid markers, subpopulation (36%) CD34+ | CD45dim/neg, CD19+, CD10++, CD20−, Tdt+, CD22+, CD cyt79a+, CD38+, HLADR+, CD123dim/neg, CD58+, CD66c−, cytIgM−, no myeloid markers, CD34hetero/+, no T-cell markers, CD99++ |
| Blast count at diagnosis (bone marrow) | 69% | 74% |
| CNS engagement of leukemia | No | No |
| Cytogenetics (bone marrow at diagnosis) | ||
| Karyotyping with G-banding | 46,XX,t(11;12)(q21;p13)[6]/46,XX[19] | 46,XX,t(11;12)(q23;p13)[5]/47,XX,sl, t(1;12)(p13;p13),+der(1)t(1;12)(p13;p13)[9]/46,XX[3] |
| FISH | nuc ish(ETV6x2,RUNX1x3)(ETV6 con RUNX1x1)[145/206],(ETV6x1,RUNX1x3)(ETV6 con RUNX1x1)[12/206] | nuc ish(ETV6x2,RUNX1x3)(ETV6 con RUNX1x1)[98/222],(ETV6x1,RUNX1x3)(ETV6 con RUNX1x1)[98/222] |
| ArrayCGH | No detectable copy number changes | No additional finding |
| Interpretation | Main clone with t(11;12) and ETV6-RUNX1 (70%), subclone with additional delETV6 (6%) | Main clone with t(11;12) and ETV6-RUNX1 (88%), subclone with additional delETV6 and t(1;12) with extra der(1)t(1;12) (44%) |
| Image cytometric DNA analysis (ICDA) | Diploid (DNA index: 0.5, S-phase 8%) | Diploid (DNA index: 1, S-phase 8%) |
| Treatment protocol | NOPHO-ALL 2008 standard risk arm | NOPHO-ALL 2008 standard risk arm |
| Stem cell transplantation | No | No |
| Minimal residual disease | ||
| Day 15 | <0.1% | <0.1% |
| Day 29 | <0.1% | <0.01% |
| Day 79 | <0.01% | <0.01% |
| Complications and treatment related toxicities | Gastroenteral chlostridium difficile infection. Bilateral purulent heamophilus influenzae conjunctivitis. HSV keratitis. Severe varicella infection with concurrent hepatitis of unknown etiology | Vincristine neuropathy with remaining muscular weakness in lower limbs. Acute ITP after end of intense treatment phase, spontaneous regression after steroid treatment |
| Adjustments to treatment protocol | Dose reduction of high-dose methotrexate due to high top-concentrations and delayed excretion with renal toxicity | Dose reduction of Vincristine due to toxicity (peripheral neuropathy) |
| Relapse | No. Currently in complete remission 5.5 y after diagnosis | No. Currently in complete remission 5 y after diagnosis |
| Current growth and developmental parameters | ||
| Height | −1.64 SD | −1.72 SD |
| Weight | −0.94 SD | −1.3 SD |
| Head size | Not available | Not available |
| Psychomotor development | Normal | Normal |
CGH, comparative genomic hybridization; HSV, Herpes simplex virus; ITP, immune thrombocytopenic purpura; NOPHO, Nordic Society of Paediatric Haematology and Oncology.