Jane Stevens

Five new pedigrees with inherited RUNX1 mutations causing familial platelet disorder with propensity to myeloid malignancy

Familial platelet disorder with propensity to myeloid malignancy (FPD/AML) is an autosomal dominant syndrome characterized by platelet abnormalities and a predisposition to myelodysplasia (MDS) and/or acute myeloid leukemia (AML). The disorder, caused by inherited mutations in RUNX1, is uncommon with only 14 pedigrees reported. We screened 10 families with a history of more than one first degree relative with MDS/AML for inherited mutations in RUNX1. Germ- line RUNX1 mutations were identified in 5 pedigrees with a 3:2 predominance of N-terminal mutations. Several affected members had normal platelet counts or platelet function, features not previously reported in FPD/AML. The median incidence of MDS/AML among carriers of RUNX1 mutation was 35%. Individual treatments varied but included hematopoietic stem cell transplantation from siblings before recognition of the inherited leukemogenic mutation. Transplantation was associated with a high incidence of complications including early relapse, failure of engraftment, and posttransplantation lymphoproliferative disorder. Given the small size of modern families and the clinical heterogeneity of this syndrome, the diagnosis of FPD/AML could be easily overlooked and may be more prevalent than previously recognized. Therefore, it would appear prudent to screen young patients with MDS/AML for RUNX1 mutation, before consideration of sibling hematopoietic stem cell transplantation.

Microdeletions are a general feature of adult and adolescent acute lymphoblastic leukemia: Unexpected similarities with pediatric disease

We present here a genome-wide map of abnormalities found in diagnostic samples from 45 adults and adolescents with acute lymphoblastic leukemia (ALL). A 500K SNP array analysis uncovered frequent genetic abnormalities, with cryptic deletions constituting half of the detected changes, implying that microdeletions are a characteristic feature of this malignancy. Importantly, the pattern of deletions resembled that recently reported in pediatric ALL, suggesting that adult, adolescent, and childhood cases may be more similar on the genetic level than previously thought. Thus, 70% of the cases displayed deletion of one or more of the CDKN2A, PAX5, IKZF1, ETV6, RB1, and EBF1 genes. Furthermore, several genes not previously implicated in the pathogenesis of ALL were identified as possible recurrent targets of deletion. In total, the SNP array analysis identified 367 genetic abnormalities not corresponding to known copy number polymorphisms, with all but two cases (96%) displaying at least one cryptic change. The resolution level of this SNP array study is the highest used to date to investigate a malignant hematologic disorder. Our findings provide insights into the leukemogenic process and may be clinically important in adult and adolescent ALL. Most importantly, we report that microdeletions of key genes appear to be a common, characteristic feature of ALL that is shared among different clinical, morphological, and cytogenetic subgroups.

A novel inherited mutation of the transcription factor RUNX1 causes thrombocytopenia and may predispose to acute myeloid leukaemia

Summary.  The RUNX1 (AML1, CBFA2) gene is a member of the runt transcription factor family, responsible for DNA binding and heterodimerization of other non‐DNA binding transcription factors. RUNX1 plays an important part in regulating haematopoiesis and it is frequently disrupted by illegitimate somatic recombination in both acute myeloid and lymphoblastic leukaemia. Germline mutations of RUNX1 have also recently been described and are dominantly associated with inherited leukaemic conditions. We have identified a unique point mutation of the RUNX1 gene (A107P) in members of a family with autosomal dominant inheritance of thrombocytopenia. One member has developed acute myeloid leukaemia (AML).

Serum selenium concentration at diagnosis and outcome in patients with haematological malignancies.

We have previously reported presentation serum selenium level to be predictive of outcome in diffuse large B–cell lymphoma. This has now been studied in a further 430 patients, 163 with acute myeloid leukaemia (AML), 156 with Hodgkin Lymphoma (HL), and 111 with Follicular Lymphoma (FL). Serum selenium was below the UK normal reference range in 45% of patients, and correlated with serum albumin (r = 0·24–0·46, P < 0·001–0·003) in all tumour types. Independent predictors of presentation selenium were; French‐American‐British subtype and albumin (P < 0·001 for both) in AML, haemoglobin (P = 0·002) and B‐symptoms (P = 0·01) in HL, and albumin (P < 0·001) in FL. In AML and HL, response to first line therapy was lower in patients with low serum selenium, but selenium was no longer predictive of response when other variables were entered into a multivariate model. Low selenium was also associated with a worse overall survival in FL [Hazard Ratio (HR) 2·3, 95% confidence interval (CI) 1·4, 4·0] and a trend to a worse overall survival in AML (HR 1·43, 95% CI 0·96, 2·13) by univariate Cox regression analysis, but not by multivariate analysis. In conclusion, low serum selenium is associated with a worse outcome in patients with haematological malignancies, but is not independently predictive, suggesting that it reflects other factors.

Patterns of recruitment into acute myeloid leukaemia (AML) 15 and outcome for young patients with AML at a single referral centre.

This study assessed the recruitment to an acute myeloid leukaemia (AML) trial (AML15) in a single centre, evaluated whether outcome was influenced by trial entry and whether the trial population could be considered representative of all AML patients by retrospective comparison of patient characteristics, trial entry and outcome for 81 consecutive patients (<60 years). All patients were considered for trial entry, however the trial was not offered to 12 (15%) patients. These patients had a worse outcome than the 69 (85%) patients that were invited to participate (P = 0·04). Sixteen patients (23%) invited to participate in the trial declined and were treated on equivalent protocols. These patients had a similar outcome to those who accepted entry into the trial (P = 0·2). These results suggested that physicians exert a selection bias when evaluating patients for trial entry. Thus the overall survival estimates generated from large phase III trials may indicate that the outcome for patients with AML is better than the outcome experienced in the ‘real’ world. Furthermore, patients who are considered appropriate for randomization into a trial, but decline entry, experience a similar outcome to those treated on trial when treated in an equivalent manner.