ABSTRACT
The presence of genetic alterations was investigated by SNP array in combination with conventional and spectral karyotyping and fluorescence in situ hybridization analysis of 75 consecutive pediatric bone marrow samples. The samples were collected at diagnosis from all children diagnosed with malignant hematological disease between 2006 and 2010 at a single diagnostic center in Gothenburg, Sweden. Conventional cytogenetic and molecular genetics techniques are up to this date essential for the clinical laboratories but there is a need for higher resolution techniques in order to identify new genetic markers that eventually can improve the management of these disorders. Here, we conclude that the addition of SNP array-based karyotyping combined with conventional cytogenetics increase the diagnostic accuracy of pediatric hematological malignancies. The two techniques enhance the cytogenetic image and should not be contrasted as they meet distinct important roles. Since balanced translocations cannot be detected with the SNP arrays of today and tumor-specific translocations are very important diagnostic and prognostic indicators we suggest that SNP-based array is a valuable adjuvant tool in the cytogenetic diagnostics of pediatric leukemias but cannot replace currently used techniques, i.e. G-banding, SKY and FISH analysis.
Subject(s)
Chromosome Aberrations , DNA Copy Number Variations , Hematologic Neoplasms/diagnosis , Hematologic Neoplasms/genetics , Child , Humans , In Situ Hybridization, Fluorescence , Karyotyping , Oligonucleotide Array Sequence Analysis , Polymorphism, Single NucleotideABSTRACT
Acquired loss of material from chromosome 5 in bone marrow cells is common in myelodysplastic syndromes (MDS) and acute myelocytic leukemia (AML). In this study, we have applied fluorescence in situ hybridization (FISH) analyses with probes for the three regions 5p15.2, 5q31, 5q33-q34, and whole chromosome 5 painting probes (WCP 5) to investigate what further information could be gained regarding the cytogenetic abnormalities of chromosome 5 in 35 patients with MDS or AML. With FISH, a del(5q) was found in all patients except for two. Translocations of material from chromosome 5 were found in 10 patients. Among 16 patients with clones of monosomy 5 seen by cytogenetics, 14 had deletions or translocations. Different breakpoints on chromosome 5 were observed. In conclusion, the extended FISH analyses yielded additional information about chromosome 5 abnormalities in 60% of the patients. Of interest is the finding of a high proportion of translocations and that monosomy 5 occurs less often than is generally believed.
Subject(s)
Chromosome Deletion , Chromosomes, Human, Pair 5/genetics , Leukemia, Myeloid, Acute/genetics , Monosomy/genetics , Myelodysplastic Syndromes/genetics , Translocation, Genetic/genetics , Aged , Aged, 80 and over , Cytogenetic Analysis , Female , Genetic Predisposition to Disease , Humans , In Situ Hybridization, Fluorescence , Male , Middle AgedABSTRACT
Mastocytosis is a rare disease characterized by proliferation of mast cells in one or several organs. With conventional cytogenetics about 35% of the patients have chromosomally abnormal clones in bone marrow cells. It has been proposed to include the mast cell disease among the myeloproliferative disorders, in which trisomy for chromosome 8 and 9 can appear in the bone marrow cells. In this study bone marrow cells from eight patients with mastocytosis, two had as well an associated hematological disease, have been examined with fluorescence in situ hybridization (FISH) for enumeration of chromosome no8 and 9. In conventional cytogenetics two patients had clones with del(20) and 47,XY,+14/45, X,-Y, respectively. None of the patients with mastocytosis had clones with trisomy 8 or 9 with either cytogenetics or FISH.
