Low CD23 expression correlates with high CD38 expression and the presence of trisomy 12 in CLL.

Chronic lymphocytic leukemia (CLL) is characterized by a neoplastic B-cell population coexpressing CD5 and CD23; however, the expression of CD23 is variable. In human, two isotypes of CD23 have been identified and related to different functions. The aim of our study was to investigate the relative expression of the two CD23 isotypes in CLL and find possible correlation with other prognostic factors. The expression of CD23 isotypes was analyzed in 54 cases of CLL by polymerase chain reaction (PCR) and quantitative real-time PCR. The immunophenotype of CLL cells was characterized by flow cytometry. We demonstrated a higher CD23a than CD23b expression of CLL cells. Our results also revealed two subsets of CLL cases with a distinct CD23 isotype expression pattern. Thirty-two percent of the cases (group CLL1) showed both low mRNA level of CD23 isotypes and high protein levels of CD20 and CD38 in contrast to group CLL2 with high CD23 mRNA levels. By correlating these results to the presence of prognostic factors determined by fluorescence in situ hybridization, we found that the majority of the cases of group CLL1 (14/17) carried trisomy 12. In summary, our results confirm a high CD23a/CD23b ratio of the CLL cells and demonstrate that in a subset of CLL cases, low CD23 expression together with high CD20 and CD38 expressions may serve as a surrogate for trisomy 12. Copyright © 2015 John Wiley & Sons, Ltd.

Preserved global histone H4 acetylation linked to ETV6-RUNX1 fusion and PAX5 deletions is associated with favorable outcome in pediatric B-cell progenitor acute lymphoblastic leukemia.

Epigenetic dysregulation is a hallmark of cancer executed by a number of complex processes the most important of which converge on DNA methylation and histone protein modifications. Epigenetic marks are potentially reversible and thus promising drug targets. In the setting of acute lymphoblastic leukemia (ALL) they have been associated with clinicopathological features including risk of relapse or molecular subgroups of the disease. Here, using immunocytochemistry of bone marrow smears from diagnosis, we studied global histone H4 acetylation, whose loss was previously linked to treatment failure in adults with ALL, in pediatric patients. We demonstrate that preserved global histone H4 acetylation is significantly associated with favorable outcome (RFS, EFS, OS) in children with B cell progenitor (BCP) ALL, recapitulating the findings from adult populations. Further, for the first time we demonstrate differential histone H4 acetylation in molecular subclasses of BCP-ALL including cases with ETV6-RUNX1 fusion gene or PAX5 deletion or deletions in genes linked to B cell development. We conclude global histone H4 acetylation is a prognostic marker and a potential therapeutic target in ALL.

[Microdeletion 12p12 involving SOX5 gene: a new syndrome with developmental delay]. / Microdeleción 12p12 que incluye el gen SOX5: un nuevo síndrome con alteracion del neurodesarrollo.

INTRODUCTION: The SOX5 gene encodes a transcription factor involved in the regulation of chondrogenesis and the development of the nervous system. CASE REPORT: We report a 10 years-old girl with developmental delay, behavior problems and dysmorphic features of this new syndrome with developmental delay. She had a 12p12 deletion involving SOX5. CONCLUSIONS: We review the reported cases, intragenic SOX5 deletions and larger 12p12 deletions encompassing SOX5. We analyze the genotype-phenotype associations and the genes involved in our patient.

TITLE: Microdelecion 12p12 que incluye el gen SOX5: un nuevo sindrome con alteracion del neurodesarrollo.Introduccion. El gen SOX5 codifica un factor de transcripcion implicado en la regulacion de la condrogenia y el desarrollo del sistema nervioso. Caso clinico. Niña de 10 anos con discapacidad intelectual, alteracion conductual y malformaciones menores de este nuevo sindrome con alteracion en el neurodesarrollo, con una delecion 12p12 que incluye el gen SOX5. Conclusiones. Se revisan los casos publicados tanto de deleciones intragenicas de SOX5 como de deleciones mas grandes que incluyen este gen, y se analizan las correlaciones genotipo-fenotipo y los genes implicados en esta paciente.

Heterogeneous chromosome 12p deletion is an independent adverse prognostic factor and resistant to bortezomib-based therapy in multiple myeloma.

The deletion of 12p (del(12p)) has been described as a novel negative prognostic marker in multiple myeloma (MM) and has gained increasing attention in recent years. However, its impact on MM is still controversial. In this study, we comprehensively evaluated the clinical impact of 12p13 deletion using fluorescence in situ hybridization (FISH) on 275 newly diagnosed MM cases treated in a prospective, non-randomized clinical trial (BDH 2008/02). The results showed that deletion of 12p13 was detected in 10.5% of newly diagnosed cases and associated with multiple indicators for high tumor burden including ISS III, BM plasmacytosis larger than 50%, and renal lesion. Moreover, the cases with 12p13 deletion typically had higher incidence of del(17p), IGH translocation and t(4;14). Patients with del(12p) conferred significantly adverse prognosis for PFS and OS, even in patients subjected to bortezomib-based therapy. When adjusted to the established prognostic variables including del(13q), del(17p), t(4;14), amp(1q21), ISS stage and LDH, del(12p13) remained the powerful independent adverse factor for PFS (P = 0.007) and OS (P = 0.032). In addition, del(12p13) combined with high ß2-MG, high LDH and bone lesion can further identify subpopulations with high-risk features. Our results strongly supported that del(12p13) can be used as a valuable prognostic marker in MM.

Imaging genetics and psychiatric disorders.

Imaging genetics is an integrated research method that uses neuroimaging and genetics to assess the impact of genetic variation on brain function and structure. Imaging genetics is both a tool for the discovery of risk genes for psychiatric disorders and a strategy for characterizing the neural systems affected by risk gene variants to elucidate quantitative and mechanistic aspects of brain function implicated in psychiatric disease. Early studies of imaging genetics included association analyses between brain morphology and single nucleotide polymorphisms whose function is well known, such as catechol-Omethyltransferase (COMT) and brain-derived neurotrophic factor (BDNF). GWAS of psychiatric disorders have identified genes with unknown functions, such as ZNF804A, and imaging genetics has been used to investigate clues of the biological function of these genes. The difficulty in replicating the findings of studies with small sample sizes has motivated the creation of largescale collaborative consortiums, such as ENIGMA, CHARGE and IMAGEN, to collect thousands of images. In a genome-wide association study, the ENIGMA consortium successfully identified common variants in the genome associated with hippocampal volume at 12q24, and the CHARGE consortium replicated this finding. The new era of imaging genetics has just begun, and the next challenge we face is the discovery of small effect size signals from large data sets obtained from genetics and neuroimaging. New methods and technologies for data reduction with appropriate statistical thresholds, such as polygenic analysis and parallel independent component analysis (ICA), are warranted. Future advances in imaging genetics will aid in the discovery of genes and provide mechanistic insight into psychiatric disorders.

Paediatric B-cell precursor acute lymphoblastic leukaemia with t(1;19)(q23;p13): clinical and cytogenetic characteristics of 47 cases from the Nordic countries treated according to NOPHO protocols.

The translocation t(1;19)(q23;p13)/der(19)t(1;19) is a risk stratifying aberration in childhood B-cell precursor acute lymphoblastic leukaemia (BCP ALL) in the Nordic countries. We have identified 47 children/adolescents with t(1;19)/der(19)t(1;19)-positive BCP ALL treated on two successive Nordic Society of Paediatric Haematology and Oncology (NOPHO) protocols between 1992 and 2007 and have reviewed the clinical and cytogenetic characteristics of these cases, comprising 1·8% of all cases. The translocation was balanced in 15 cases (32%) and unbalanced in 29 cases (62%). The most common additional chromosome abnormalities were del(9p), i(9q), del(6q), and del(13q). The median age was 7 years, the median white blood cell (WBC) count was 16 × 10(9)/l, and the female/male ratio was 1·2. The predicted event-free survival (EFS) at 5 and 10 years was 0·79, whereas the predicted overall survival (OS) at 5 and 10 years was 0·85 and 0·82, respectively. Nine patients had a bone marrow relapse after a median of 23 months; no patient had a central nervous system relapse. Additional cytogenetic abnormalities, age, gender, WBC count or whether the t(1;19) was balanced or unbalanced did not influence EFS or OS. Compared to cases with t(12,21) and high hyperdiploidy, EFS was similar, but overall survival was worse in patients with t(1;19)/der(19)t(1;19) (P = 0·004).

The finding of a reciprocal whole-arm translocation t(X;12)(p10;p10) in association with atypical chronic myeloid leukaemia.

Atypical chronic myeloid leukaemia (aCML) belongs to the myeloproliferative/myelodysplastic category of haematological disease. Main characteristics are marked dysgranulopoiesis, bone marrow dysfunction and the failure to demonstrate the presence of the Philadelphia chromosome or BCR/ABL fusion gene normally associated with CML t(9;22)(q34;q11). It carries a poor prognosis with limited therapeutic options available. Most cases of aCML have one or more karyotypic abnormalities. We highlight a clinical presentation of aCML associated with an acquired reciprocal whole-arm translocation (WAT), t(X;12)(p10;p10), which to our knowledge has not yet been described. We also discuss how such a translocation might lead to tumorigenesis.

Protocols for cytogenetic studies of human embryonic stem cells.

All cultured cells develop chromosome changes over time, including cultures of human embryonic stem cells (hESC), but only those cells with adaptive chromosomes changes survive. The most frequent chromosome changes in hESC cultures are trisomy 12 and trisomy 17. Cells with these trisomies are indistinguishable from normal cells by appearance and also demonstrate typical markers of pluripotency, making them difficult to identify without cytogenetic analysis. Early detection of these cells is essential since cells with trisomy 12 and 17 can replace the normal cell population in 5-10 passages. Cytogenetic analysis using G-banding is considered to be the gold standard for detecting chromosome abnormalities and, when used in combination with interphase FISH, provides a sensitive method for early detection of cytogenetic aberrations, such as full and partial trisomies of chromosomes 12 and 17. The following discussion describes the cytogenetic methods used in our laboratory to study cultured hESCs, along with recommendations for integrating these methods into a plan for routine cell line quality control.

ETV6/GOT1 fusion in a case of t(10;12)(q24;p13)-positive myelodysplastic syndrome.

The ETV6/GOT1 fusion, resulting from t(10;12) (q24;p13), has been recently described in a myelodysplastic syndrome. We reported a second case of t(10;12)-positive myelodysplastic syndrome in whom fluorescent in situ hybridization confirmed the non-random translocation but molecular biology analyses revealed a ETV6/GOT1 chimera varying from the first case described.

Do cytogenetic abnormalities precede morphologic abnormalities in a developing malignant condition?

Cytogenetic evaluation of bone marrow and neoplastic tissues plays a critical role in determining patient management and prognosis. Here, we highlight two cases in which the cytogenetic studies challenge the common practice of using hematologic and morphologic changes as key factors in malignant disease management. The first case is that of a lymph node sample from a 40-yr-old non-Hodgkin's lymphoma (NHL) patient sent for determination of disease progress. Hematologic studies showed no evidence of transformation to high-grade NHL (>15% blasts with rare mitotic figures). Cytogenetic studies of lymph node showed multiple clonal abnormalities, most notably a der(18) from a t(14;18) which is associated with high-grade NHL. After two cycles of chemotherapy with fludarabine, the patient did not show any clinical response, suggesting possible progression to high-grade lymphoma. The second case is of a patient with a history of human immunodeficiency virus and blastic natural killer leukemia/lymphoma. Hematologic studies of ascitic fluid classified the patient as having pleural effusion lymphoma whereas bone marrow analysis showed no malignancy. Bone marrow cytogenetic studies showed multiple clonal abnormalities including a t(8;14), which is commonly associated with Burkitt's lymphoma (BL). To our knowledge, this is the first case wherein a morphologically normal bone marrow showed presence of clonal abnormalities consistent with BL or Pleural effusion lymphoma. After two cycles of CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy, the patient's general condition and ascitis improved and she was discharged. These studies clearly demonstrate that genetic changes often precede morphologic changes in a developing malignant condition. Therefore, the critical information needed for care of patients with malignant disorders may be incomplete or inaccurate if cytogenetic evaluation is overlooked.

Osteopoikilosis, short stature and mental retardation as key features of a new microdeletion syndrome on 12q14.

This report presents the detection of a heterozygous deletion at chromosome 12q14 in three unrelated patients with a similar phenotype consisting of mild mental retardation, failure to thrive in infancy, proportionate short stature and osteopoikilosis as the most characteristic features. In each case, this interstitial deletion was found using molecular karyotyping. The deletion occurred as a de novo event and varied between 3.44 and 6 megabases (Mb) in size with a 3.44 Mb common deleted region. The deleted interval was not flanked by low-copy repeats or segmental duplications. It contains 13 RefSeq genes, including LEMD3, which was previously shown to be the causal gene for osteopoikilosis. The observation of osteopoikilosis lesions should facilitate recognition of this new microdeletion syndrome among children with failure to thrive, short stature and learning disabilities.

High cognitive functioning and behavioral phenotype in Pallister-Killian syndrome.

Pallister-Killian syndrome (PKS) is a rare syndrome of multiple congenital anomalies attributable to the presence of a mosaic supernumerary isochromosome 12p. The syndrome presents with a recognizable pattern of findings including: pigmentary skin changes, characteristic facial features (sparse anterior scalp hair, flattened midface, macrostomia, and coarsening of the facial features), and developmental delay. The developmental phenotype of PKS is quite variable, but most are considered to fall into the profound range of developmental retardation. We report on an individual with classical features of PKS with development significantly better than that reported in the literature. Developmental and behavioral testing in this individual alters the range of developmental expectation in PKS, and highlights the need for consideration of chromosomal analysis in individuals with normal or near-normal intelligence if other physical phenotypic features of PKS are present.

The influence of different chromosomal aberrations on molecular cytogenetic parameters in chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (B-CLL) is the most common leukemia of adults in Western countries. The most frequent recurring chromosomal aberrations identified in B-CLL patients are trisomy 12 and deletions of 13q, 17p, and 11q. Cases with deletions of 11q and 17p have a poor prognosis, whereas cases with deletions in 13q have a favorable prognosis. It was previously shown that CLL patients with trisomy 12 and del(13)(q14) have a higher rate of asynchronous replication of normal structural genes when compared to those with normal karyotypes. We studied the replication pattern of the structural locus 21q22 and the imprinted gene SNRPN and its telomere (15qter) and the random aneuploidy of chromosomes 9 and 18 in CLL patients with trisomy 12 and deletions of 11q and 17p, and compared the results to those of CLL patients without these aberrations and to healthy controls. Random aneuploidy rate was higher in the group of patients with trisomy 12 as compared to all other groups. The replication pattern with higher asynchronous pattern was found in both aberration groups compared to the CLL patients without the aberrations and to the control group with involvement of 21q22 and 15qter, whereas the highest synchronous group was found in the 2 aberrations CLL patient groups compared to the other groups with the imprinted locus SNRPN. The existence and significance of chromosomal aberrations in CLL have a deleterious effect on the processes of cell cycle and gene replication and may have biological and prognostic implications.