Acute myeloid leukaemia with 8p11 (MYST3) rearrangement: an integrated cytologic, cytogenetic and molecular study by the groupe francophone de cytogénétique hématologique.

Thirty cases of acute myeloid leukaemia (AML) with MYST histone acetyltransferase 3 (MYST3) rearrangement were collected in a retrospective study from 14 centres in France and Belgium. The mean age at diagnosis was 59.4 years and 67% of the patients were females. Most cases (77%) were secondary to solid cancer (57%), haematological malignancy (35%) or both (8%), and appeared 25 months after the primary disease. Clinically, cutaneous localization and disseminated intravascular coagulation were present in 30 and 40% of the cases, respectively. AMLs were myelomonocytic (7%) or monocytic (93%), with erythrophagocytosis (75%) and cytoplasmic vacuoles (75%). Immunophenotype showed no particularity compared with monocytic leukaemia without MYST3 abnormality. Twenty-eight cases carried t(8;16)(p11;p13) with MYST3-CREBBP fusion, one case carried a variant t(8;22)(p11;q13) and one case carried a t(8;19)(p11;q13). Type I (MYST3 exon 16-CREBBP exon 3) was the most frequent MYST3-CREBBP fusion transcript (65%). MYST3 rearrangement was associated with a poor prognosis, as 50% of patients deceased during the first 10 months. All those particular clinical, cytologic, cytogenetic, molecular and prognostic characteristics of AML with MYST3 rearrangement may have allowed an individualization into the World Health Organization classification.

Hyperdiploid karyotypes in acute myeloid leukemia define a novel entity: a study of 38 patients from the Groupe Francophone de Cytogenetique Hematologique (GFCH).

A series of 38 patients with acute myeloblastic leukemia (AML) with 49 or more chromosomes and without structural abnormalities was selected within the Groupe Francophone de Cytogénétique Hématologique (GFCH) to better define their characteristics. The median age of the patients was 65 years, and all FAB subtypes were represented. Although all chromosomes were gained, some seems to prevail: chromosome 8 (68%), 21 (47%), 19 (37%), and 13 and 14 (34% each). Since MLL rearrangement leads patients in a group with an unfavorable prognosis, search for cryptic rearrangements of MLL was performed in 34 patients and showed abnormalities in 5 (15%). When we applied the most frequent definition of complex karyotypes (three or more abnormalities), all patients with high hyperdiploid AML fall in the unfavorable category. Among the 18 patients without MLL rearrangement receiving an induction therapy, 16 (89%) reached CR and 6 (33%) were still alive after a 31-month median follow-up (14-61 months). Although this study was retrospective, these results suggest that high hyperdiploid AML without chromosome rearrangement seems to be a subgroup of uncommon AML (less than 1%), and may be better classified in the intermediate prognostic group.

Molecular cytogenetic study of 126 unselected T-ALL cases reveals high incidence of TCRbeta locus rearrangements and putative new T-cell oncogenes.

Chromosomal aberrations of T-cell receptor (TCR) gene loci often involve the TCRalphadelta (14q11) locus and affect various known T-cell oncogenes. A systematic fluorescent in situ hybridization (FISH) screening for the detection of chromosomal aberrations involving the TCR loci, TCRalphadelta (14q11), TCRbeta (7q34) and TCRgamma (7p14), has not been conducted so far. Therefore, we initiated a screening of 126 T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma cases and 19 T-ALL cell lines using FISH break-apart assays for the different TCR loci. Genomic rearrangements of the TCRbeta locus were detected in 24/126 cases (19%), most of which (58.3%) were not detected upon banding analysis. Breakpoints in the TCRalphadelta locus were detected in 22/126 cases (17.4%), whereas standard cytogenetics only detected 14 of these 22 cases. Cryptic TCRalphadelta/TCRbeta chromosome aberrations were thus observed in 22 of 126 cases (17.4%). Some of these chromosome aberrations target new putative T-cell oncogenes at chromosome 11q24, 20p12 and 6q22. Five patients and one cell line carried chromosomal rearrangements affecting both TCRbeta and TCRalphadelta loci. In conclusion, this study presents the first inventory of chromosomal rearrangements of TCR loci in T-ALL, revealing an unexpected high number of cryptic chromosomal rearrangements of the TCRbeta locus and further broadening the spectrum of genes putatively implicated in T-cell oncogenesis.

Low T-cell chimerism is not followed by graft rejection after nonmyeloablative stem cell transplantation (NMSCT) with CD34-selected PBSC.

We investigate the feasibility of CD34-selected peripheral blood stem cell (PBSC) transplantation followed by pre-emptive CD8-depleted donor lymphocyte infusions (DLI) after a minimal conditioning regimen. Six patients with advanced hematological malignancies ineligible for a conventional myeloablative transplant (n=5) or metastatic renal cell carcinoma (n=1), and with an HLA-identical (n=4) or alternative (n=2) donor were included. The nonmyeloablative conditioning regimen consisted in 2 Gy TBI alone (n=4), 2 Gy TBI and fludarabine (RCC patient, n=1) or cyclophosphamide and fludarabine (patient who had previously received 12 Gy TBI, n=1). Post transplant immunosuppression was carried out with cyclosporin (CyA) and mycophenolate mofetil (MMF). Initial engraftment was achieved in all patients. One out of six patients (17%) experienced grade > or =2 acute GVHD only after abrupt cyclosporin discontinuation and alpha interferon therapy for life-threatening tumor progression. T-cell chimerism was 23% (19-30) on day 28, 32% (10-35) on day 100, 78% (49-95) on day 180 and 99.5% (99-100) on day 365. Three out of four patients who had measurable disease before the transplant experienced a complete response. We conclude that CD34-selected NMSCT followed by CD8-depleted DLI is feasible and preserves engraftment and apparently also the graft-versus-leukemia (GVL) effect. Further studies are needed to confirm this encouraging preliminary report.

t(5;14)/HOX11L2-positive T-cell acute lymphoblastic leukemia. A collaborative study of the Groupe Français de Cytogénétique Hématologique (GFCH).

To accurately estimate the incidence of HOX11L2 expression, and determine the associated cytogenetic features, in T-cell acute lymphoblastic leukemia (T-ALL), the Groupe Français de Cytogénétique Hématologique (GFCH) carried out a retrospective study of both childhood and adult patients. In total, 364 patients were included (211 children

[Clinical case of the month. Constipation and abdominal mass syndrome in a 51-year-old patient]. / Le cas clinique du mois. Constipation et syndrome de masse abdominale chez une patiente de 51 ans.

A 51-year old patient consults for abdominal swelling and persistent constipation. Clinical exploration shows the presence of a left iliac fossa tumor corresponding to a papillary serous adenocarcinoma of the fallopian tube after macroscopic and microscopic examination. The diagnostic and therapeutic problems caused by this rare gynecologic tumor are discussed.

Submicroscopic terminal deletions and duplications in retarded patients with unclassified malformation syndromes.

Unbalanced submicroscopic subtelomeric chromosomal rearrangements represent a significant cause of unexplained moderate to severe mental retardation with and without phenotypic abnormalities. We investigated 254 patients (102 from Zürich, 152 from Liège) for unbalanced subtelomeric rearrangements by using fluorescence in situ hybridisation with probes mapping to 41 subtelomeric regions. Mental retardation combined with a pattern of dysmorphic features, with or without major malformations, and growth retardation and a normal karyotype by conventional G-banding were the criteria of inclusion. Selection criteria were more restrictive for the Zürich series in terms of clinical and cytogenetic pre-investigation. We found 13 unbalanced rearrangements and two further aberrations, which, following the investigation of other family members, had to be considered as variants without influence on the phenotype. The significant aberrations included three de novo deletions (two of 1pter, one of 5pter), three de novo duplications (8pter, 9pter, Xpter), one de novo deletion 13qter-duplication 4qter, and five familial submicroscopic translocations [(1q;18p), (2q;4p), (2p;7q), (3p;22q), (4q;10q), (12p;22q)], most of them with several unbalanced offspring with deletion-duplication. Although the incidence of abnormal results was higher (10/152) in the Liège versus the Zürich series (3/102), similar selection criteria in Zürich as in Liège would have resulted in an incidence of 7/106 and thus similar figures. In our series, submicroscopic unbalanced rearrangements explain the phenotype in 13/254 study probands. The most important selection criterion seems to be the presence of more than one affected member in a family. An examination of subtelomeric segments should be included in the diagnostic work-up of patients with unexplained mental retardation combined with physical abnormalities, when a careful conventional examination of banded chromosomes has yielded a normal result and a thorough clinical examination does not lead to another classification. The proportion of abnormal findings depends strongly on selection criteria: more stringent selection can eliminate some examinations but necessitates a high workload for experienced clinical geneticists. Once the costs and workload of screening are reduced, less selective approaches might finally be more cost-effective.

Episphalosomic syndrome : a MCA syndrome ressembling Fanconi anemia, with increased baseline level of chromosome breaks but no hypersensivity to clastogens.

We describe a child with facial dysmorphism (trigonocephaly, epicanthus, upturned nose, small ears), thumb hypoplasia, micropenis, jejunal atresia and moderate mental retardation with dysphasia. Cytogenetic workup revealed high spontaneous level of chromosomal aberrations (without specific pattern and no quadriradial figures) and borderline to absent hypersensitivity to mitomycin C, making a diagnosis of Fanconi anemia unlikely. The child described here shares similarities with a small number of previous reports. We suggest to refer to this entity as episphalosomic syndrome. Episphalosomic syndrome shows some clinical overlap with Fanconi anemia, but lacks its cytogenetic hallmark. The hematological complications of Fanconi anemia have not been reported in this entity.

Translocation (16;17)(q22;p13) is a recurrent anomaly of aneurysmal bone cysts.

Recently, Panoutsakopoulos et al. (1999) reported 2 cases of aneurysmal bone cysts with a recurrent (16;17)(q22;p13) translocation. We present here two additional cases harboring the same translocation as well as additional chromosomal changes.

Major decrease in the incidence of trisomy 21 at birth in south Belgium: mass impact of triple test?

In South Belgium (Wallonia), the 'triple test' was introduced in 1990-1991, and is nowadays a widely accepted screening method for assessment of trisomy 21 risk in pregnancy. The 'triple test' is not regulated and can be freely performed by any biomedical lab, making epidemiological data unavailable. By contrast, cytogenetic investigations are limited to a few genetic centres, and accurate statistics can be easily built from their files. During the period 1984-1989, a total of 244 trisomy 21 (1/876 pregnancies) were diagnosed in the Genetic Centres of Liège and Loverval, 42 (17%) of them prenatally. During the period 1993-1998, 294 trisomy 21 (1/704 pregnancies) were observed, 165 (56%) of which prenatally, and more than 90% of affected pregnancies were terminated. Even after correction for late foetal loss of trisomic foetuses, the difference is highly significant, and corresponds to a theoretical shift in the incidence of trisomy 21 at birth from 1/794 to 1/1606. As no remarkable progress occurred in other non-invasive prenatal screening procedures or general health care policies in Belgium, the most reasonable explanation is the use on a large scale of triple test by pregnant women, and the election of termination for most affected pregnancies.

Inv(12)(q15q24): a nonrandom change associated with myelodysplasia?

A patient with refractory anemia and a paracentric inversion of chromosome 12, inv(12)(q15q24), is described. This is the second reported case with this chromosome anomaly, suggesting that this rearrangement is a rare but nonrandom change associated with myelodysplastic syndromes.

Deletion of the 5'-ABL region: a recurrent anomaly detected by fluorescence in situ hybridization in about 10% of Philadelphia-positive chronic myeloid leukaemia patients.

Inclusion of the BCR-ABL ES probe in routine cytogenetics led to the identification of a subgroup of Philadelphia positive (Ph+) chronic myeloid leukaemia patients characterized by a 5'-ABL deletion. This anomaly was observed in 5/51 cases (9.8%). Cytological and clinical data suggest that the 5'-ABL deletion may be associated with dysplastic features of polymorphonuclear cells and metamyelocytes and a short chronic phase duration.

MLL amplification in myeloid leukemias: A study of 14 cases with multiple copies of 11q23.

We here report the clinical, cytogenetic, fluorescence in situ hybridization (FISH), and Southern blot data on 14 patients with a myeloid malignancy and structural aberration of chromosome band 11q23 associated with overrepresentation or amplification of the MLL gene. The number of copies of MLL varied from three (two cases) to a cluster consisting of multiple hybridization spots. Together with previous reports, available data indicate that amplification of 11q23/MLL is a recurrent genetic change in myeloid malignancy. It affects mainly elderly patients and is often associated with dysplastic bone marrow changes or with complex karyotypic aberrations, suggestive of genotoxic exposure. It is associated with a poor prognosis. In addition, FISH analysis of nine cases with additional 11q probes showed that the overrepresented chromosomal region is generally not restricted to MLL, and Southern blot analysis indicated that amplification does not involve a rearranged copy of this gene. The significance of MLL amplification and the mechanisms by which it could play a role in leukemogenesis and/or disease progression remain to be elucidated.

A four-parameter index of marrow dysplasia has predictive value for survival in myelodysplastic syndromes.

Marrow dysplasia is a major characteristic of patients with myelodysplastic syndrome (MDS), along with marrow blastosis, cytopenia and cytogenetic anomalies. However, the impact of the degree of marrow dysplasia on survival has not been fully assessed. In this retrospective analysis of 111 patients selected according to the IPSS criteria of MDS diagnosis, the presence or absence of 21 dysplasia characteristics recognizable in bone marrow smears stained by the May-Grünwald-Giemsa method was correlated with patient survival. Using Cox proportional hazards regression analysis, megaloblastosis (MEGALO), neutrophil agranularity (AGRAN) and hypogranularity (HYPOGRAN) were highly significant predictors (p < 0.005), and Pelger-Huët anomaly (PELGHUET) a significant predictor (p = 0.05), of patient survival. The regression analysis yielded a dysplasia-based risk index (DI) where DI = 1.26 MEGALO + 0.82 AGRAN - 1.08 HYPOGRAN + 0.45 PELGHUET. The two subgroups of 60 and 47 patients with DI < or = 0 and > 0 showed highly significant differences in median survivals (2.6 vs 1.1 yrs; p <0.0001). Multivariate analysis further showed that DI offered additional predictive power that was independent of that provided by the IPSS (p=0.002 and 0.001 respectively). Analysis of survival curves stratified for IPSS and DI showed that the additional predictive power offered by inclusion of the DI essentially concerned the IPSS low/INT-1 risk categories. Further stratification for age did not improve survival prediction. The data indicate that a set of 4 dysplasia parameters can offer some prediction for survival of MDS patients in addition to that provided by the IPSS. Further multicenter studies should aim at including some form of evaluation of the degree of dysplasia in prognostic systems.

Translocation (2;3)(p21;q26) as the sole anomaly in a case of primary myelofibrosis.

Translocation t(2p;3q) is a rare but recurrent finding in myeloid disorders. We present the first case of primary myelofibrosis with t(2;3)(p21;q26) as the sole chromosomal anomaly. The comparison with the 11 other previously published myeloid-associated t(2p;3q) cases confirms that this nonrandom translocation involves a pluripotent stem cell and is associated with a poor prognosis.

Loss of the Y chromosome in bone marrow cells: results on 1907 consecutive cases of leukaemia and preleukaemia.

Loss of the Y chromosome with a resulting 45, X0 karyotype is observed in normal bone marrow cells of elderly males but also in haematological malignancies. Whether Y loss in neoplastic cells is related to the process seen in normal ageing or is part of the carcinogenic process is unknown. The present study concerns the cytogenetic data from 1907 consecutive leukaemic or preleukaemic male patients with special regard to the presence or absence of the Y chromosome. Sixty-five patients (3.4%) had a 45, X-Y clone in their bone marrow (BM) cells. Loss of Y was rare below the age of 50 but increased in older patients, reaching 25% of the men over 80. Sixteen patients (0.08%) had more than 90% X0 cells in their BM. A correlation between Y loss and leukaemia could be established in seven cases, three of which were acute myeloid leukaemia M2 subtype where -Y is known to be a secondary event. In three other cases, -Y was part of a complex karyotype. Only one patient exhibited a 45, X0 karyotype, with no other rearrangement, that could be positively correlated with the neoplastic process.

Juvenile rheumatoid arthritis and del(22q11) syndrome: a non-random association.

Del(22q11) is a common microdeletion syndrome with an extremely variable phenotype. Besides classical manifestations, such as velocardiofacial (Shprintzen) or DiGeorge syndromes, del(22q11) syndrome may be associated with unusual but probably causally related anomalies that expand its phenotype and complicate its recognition. We report here three children with the deletion and a chronic, erosive polyarthritis resembling idiopathic cases of juvenile rheumatoid arthritis (JRA). Patient 1, born in 1983, initially presented with developmental delay, facial dysmorphism, velopharyngeal insufficiency, and severe gastro-oesophageal reflux requiring G tube feeding. From the age of 3 years, he developed JRA, which resulted in severe restrictive joint disease, osteopenia, and platyspondyly. Patient 2, born in 1976, had tetralogy of Fallot and peripheral pulmonary artery stenosis. She developed slowly, had mild dysmorphic facial features, an abnormal voice, and borderline intelligence. JRA was diagnosed at the age of 5 years. The disorder followed a subacute course, with relatively mild inflammatory phenomena, but an extremely severe skeletal involvement with major osteopenia, restrictive joint disease (bilateral hip replacement), and almost complete osteolysis of the carpal and tarsal bones with phalangeal synostoses, leading to major motor impairment and confinement to a wheelchair. Patient 3, born in 1990, has VSD, right embryo-toxon, bifid uvula, and facial dysmorphism. She developed JRA at the age of 1 year. She is not mentally retarded but has major speech delay secondary to congenital deafness inherited from her mother. In the three patients, a del(22q11) was shown by FISH analysis. These observations, and five other recently published cases, indicate that a JRA-like syndrome is a component of the del(22q11) spectrum. The deletion may be overlooked in those children with severe, chronic inflammatory disorder.