Heterogeneity of the 7q36 breakpoints in the t(7;12) involving ETV6 in infant leukemia.

The t(7;12)(q36;p13) is a recurrent chromosome abnormality in infant leukemia. In these cases, the involvement of ETV6, with disruption of the gene consistently at its 5' end, has been reported by several groups. A fusion transcript between ETV6 and HLXB9 has been detected in some, but not all, reported cases of t(7;12).

Prenatal chromosomal diversification of leukemia in monozygotic twins.

Previous studies on concordant acute lymphoblastic leukemia (ALL) in identical twins have identified the leukemia as monoclonal with MLL or ETV6-RUNX1 gene fusion as early or initiating events in utero. In the latter case, postnatal latency is associated with secondary genetic events such as ETV6 deletion. We describe here a pair of infant twins with concordant acute monoblastic leukemia (AML).

Correlation of B-type natriuretic peptide level to 6-min walk test performance in patients with left ventricular systolic dysfunction.

Background: B-type natriuretic peptide (BNP) is a neurohormone that can be measured in blood and is useful in patients with congestive heart failure (CHF). We compared whole blood BNP concentrations to distance walked during a 6-min walk test in patients with CHF.

Methods: Forty-four patients with CHF underwent a 6-min walk test.

Study of 30 patients with unexplained developmental delay and dysmorphic features or congenital abnormalities using conventional cytogenetics and multiplex FISH telomere (M-TEL) integrity assay.

Cryptic subtelomeric chromosome rearrangements are a major cause of mild to severe mental retardation pointing out the necessity of sensitive screening techniques to detect such aberrations among affected patients. In this prospective study a group of 30 patients with unexplained developmental retardation and dysmorphic features or congenital abnormalities were analysed using the recently published multiplex FISH telomere (M-TEL) integrity assay in combination with conventional G-banding analysis. The patients were selected by one or more of the following criteria defined by de Vries et al.

Narrowing and genomic annotation of the commonly deleted region of the 5q- syndrome.

The 5q- syndrome is the most distinct of the myelodysplastic syndromes, and the molecular basis for this disorder remains unknown. We describe the narrowing of the common deleted region (CDR) of the 5q- syndrome to the approximately 1.5-megabases interval at 5q32 flanked by D5S413 and the GLRA1 gene.

Considering justice: an exploratory study of family therapy with adolescents.

Feminist approaches to therapy with adolescents emphasize an empowering focus on the strengths of adolescents while simultaneously insisting that therapists become aware of their own biases toward today's adolescents. However, a review of the family therapy literature finds little mention of feminist approaches for addressing injustices (e.g.

A cryptic t(5;11)(q35;p15.5) in 2 children with acute myeloid leukemia with apparently normal karyotypes, identified by a multiplex fluorescence in situ hybridization telomere assay.

The identification of specific chromosome abnormalities in acute myeloid leukemia (AML) is important for the stratification of patients into the appropriate treatment protocols. However, a significant proportion of diagnostic bone marrow karyotypes in AML is reported as normal by conventional cytogenetic analysis and it is suspected that these karyotypes may conceal the presence of diagnostically significant chromosome rearrangements. To address this question, we have developed a novel 12-color fluorescence in situ hybridization (FISH) assay for telomeric rearrangements (termed M-TEL), which uses an optimized set of chromosome-specific subtelomeric probes.

A new strategy for the detection of subtelomeric rearrangements.

We present a new strategy for the detection of subtelomeric rearrangements. This approach is based on two hybridizations with different probe sets. The first set consists of microdissected subtelomeric probes (each 5-10 megabases in size) labeled combinatorially employing 7 different fluorochromes.

Molecular cytogenetics.

Refinements in cytogenetic techniques over the past 30 years have allowed the increasingly sensitive detection of chromosome abnormalities in haematological malignancies. In particular, the advent of fluorescence in situ hybridization techniques has provided significant advances in both diagnosis and research of leukaemias. The application of new multicolour karyotyping techniques has allowed the complete dissection of complex chromosome rearrangements and provides the prospect of identifying new recurrent chromosome rearrangements.

A novel gene, NSD1, is fused to NUP98 in the t(5;11)(q35;p15.5) in de novo childhood acute myeloid leukemia.

The recurrent translocation t(5;11)(q35;p15.5) associated with a 5q deletion, del(5q), has been reported in childhood acute myeloid leukemia (AML). We report the cloning of the translocation breakpoints in de novo childhood AML harboring a cryptic t(5;11)(q35;p15.

The paired box domain gene PAX5 is fused to ETV6/TEL in an acute lymphoblastic leukemia case.

The PAX5 gene, encoding the B-cell-specific activator protein, is a critical determinant of commitment to the B-lymphocyte pathway. This gene, mapped at 9p13, is juxtaposed to the immunoglobulin heavy chain (IgH) gene as a result of the t(9;14)(p13;q32), a rare but recurring translocation found in a subset of B-cell non-Hodgkin's lymphoma cases. In all of these, this translocation results in deregulated expression of the gene product because of the proximity of IgH.

Monosomy for the most telomeric, gene-rich region of the short arm of human chromosome 16 causes minimal phenotypic effects.

We have examined the phenotypic effects of 21 independent deletions from the fully sequenced and annotated 356 kb telomeric region of the short arm of chromosome 16 (16p13.3). Fifteen genes contained within this region have been highly conserved throughout evolution and encode proteins involved in important housekeeping functions, synthesis of haemoglobin, signalling pathways and critical developmental pathways.

New concepts to improve resolution and sensitivity of molecular cytogenetic diagnostics by multicolor fluorescence in situ hybridization.

Background: Routine application of multicolor fluorescence in situ hybridization (M-FISH) technology for molecular cytogenetic diagnostics has been hampered by several technical limitations. First, when using chromosome-specific painting probes, there is a limit in cytogenetic resolution of approximately 2-3 Mb, which can mask hidden structural abnormalities that have a significant clinical effect. Second, using whole chromosome painting probes, intrachromosomal rearrangements cannot be detected and the exact localization of breakpoints is often not possible.

A mitotically stable marker chromosome negative for whole chromosome libraries, centromere probes and chromosome specific telomere regions: a novel class of supernumerary marker chromosome?

A two year-old child presented with mild developmental delay. On karyotype analysis, a supernumerary small marker chromosome (SMC) was found in all cells examined. This SMC was approximately the size of an isochromosome 18p, being symmetrical with a central constriction.

Identification of a subtle t(16;19)(p13.3;p13.3) in an infant with multiple congenital abnormalities using a 12-colour multiplex FISH telomere assay, M-TEL.

There is increasing evidence that cytogenetically invisible chromosome rearrangements are an important cause of genetic disease. Clues to the chromosomal location of these rearrangements may be provided by a specific clinical diagnosis, which can then be investigated by targeted FISH or molecular studies. However, the phenotypic features of some microdeletion syndromes are difficult to recognise, particularly in infants.

Sequence, structure and pathology of the fully annotated terminal 2 Mb of the short arm of human chromosome 16.

We have sequenced 1949 kb from the terminal Giemsa light band of human chromosome 16p, enabling us to fully annotate the region extending from the telomeric repeats to the previously published tuberous sclerosis disease 2 (TSC2) and polycystic kidney disease 1 (PKD1) genes. This region can be subdivided into two GC-rich, Alu-rich domains and one GC-rich, Alu-poor domain. The entire region is extremely gene rich, containing 100 confirmed genes and 20 predicted genes.

t(7;12)(q36;p13), a new recurrent translocation involving ETV6 in infant leukemia.

The ETV6 gene is rearranged as a result of translocations involving a wide variety of chromosomal partners. To date, 12 partner genes for ETV6 have been cloned, and a further 23 chromosomal regions have been described. We previously identified a cryptic t(7;12) with ETV6 involvement in two cases of infant leukemia.

Cytogenetic and molecular evidence of marrow involvement in extramedullary acute myeloid leukaemia.

A diagnosis of granulocytic sarcoma was made in a 2-year-old child based on the detection of myelomonocytic blasts in tissue obtained from a subcutaneous nodule with no evidence of concomitant disease in the bone marrow. The child responded to systemic chemotherapy and is in remission 3 years later. An identical clone with an in frame fusion of the MLL and AF10 genes was identified from both tissue and bone marrow samples.

Combined immunophenotyping and FISH identifies the involvement of B-cells in 5q- syndrome.

The 5q- syndrome is a distinct subtype of myelodysplastic syndrome (MDS) characterized by refractory anemia, deletion of the long arm of chromosome 5, del(5q), as the sole cytogenetic abnormality, and a low frequency of transformation to acute leukemia. Using combined immunophenotyping and fluorescence in situ hybridization (FISH), studies were carried out on bone marrow smears of three 5q- syndrome cases to identify the cell lineages carrying the 5q deletion. In all three cases, the granulocytic, monocytic, and erythroid lineages possessed the del(5q) clonal marker, whereas the T-lymphocytes did not.

An integrated map of human 6q22.3-q24 including a 3-Mb high-resolution BAC/PAC contig encompassing a QTL for fetal hemoglobin.

Genetic studies have previously assigned a quantitative trait locus (QTL) for hemoglobin F and F cells to a region of approximately 4 Mb between the markers D6S408 and D6S292 on chromosome 6q23. An initial yeast artificial chromosome contig of 13 clones spanning this region was generated. Further linkage analysis of an extended kindred refined the candidate interval to 1-2 cM, and key recombination events now place the QTL within a region of <800 kb.

Characterization of a highly complex region in Xq13 and mapping of three isodicentric breakpoints associated with preleukemia.

The chromosomal abnormality represented by an isodicentric X chromosome [idic(X)(q13)] is associated with a subset of acute myeloid leukemia (AML) and preleukemia observed in elderly females. A previous study localized the breakpoints of two acquired isodicentric X chromosomes associated with myelodysplasia to a 450-kb region proximal to the XIST gene. Here we report the construction and extensive characterization of a reliable 1-Mb P1 artificial chromosome and bacterial artificial chromosome contig covering a highly problematic region in Xq13 that includes the previously described isodicentric breakpoint region.

Multiplex fluorescence in situ hybridization and cross species color banding of a case of chronic myeloid leukemia in blastic crisis with a complex Philadelphia translocation.

Exciting new techniques in molecular cytogenetics--namely, spectral karyotyping, multiplex fluorescence in situ hybridization (M-FISH), and cross species color banding--have been recently developed. An increasing number of reports demonstrate the success of these procedures in providing additional cytogenetic information--identifying marker chromosomes and revealing the presence of previously undetected chromosomal changes. However, these procedures have their limitations, and their absolute sensitivity in the accurate identification of subtle chromosomal abnormalities remains to be established.

The tyrosine kinase abl-related gene ARG is fused to ETV6 in an AML-M4Eo patient with a t(1;12)(q25;p13): molecular cloning of both reciprocal transcripts.

The Ets variant gene 6 (ETV6/TEL) gene is rearranged in the majority of patients with 12p13 translocations fused to a number of different partners. We present here a case of acute myeloid leukemia M4 with eosinophilia (AML-M4Eo) positive for the CBFb/MYH11 rearrangement and carrying a t(1;12)(q25;p13) that involves the ETV6 gene at 12p13. By 3'rapid amplification of cDNA ends-polymerase chain reaction (3'RACE-PCR), a novel fusion transcript was identified between the ETV6 and the Abelson-related gene (ARG) at 1q25, resulting in a chimeric protein consisting of the HLH oligomerization domain of ETV6 and the SH2, SH3, and protein tyrosine kinase (PTK) domains of ARG.