RESUMO
The effects of the CYP1A1*2A genotype on susceptibility to leukemia have received particular attention in recent years because this enzyme plays a central role in the activation of carcinogens. Several polymorphisms at the CYP1A1 locus have been identified and their genotypes appear to exhibit population frequencies that depend on ethnicity. We evaluated the role of the CYP1A1*2A genotype in adults with acute lymphoblastic leukemia (ALL) by genotyping 210 patients and 228 healthy controls from the Mexican population. The frequency of the CC genotype was 8% (18/228) in the control group and 42% (88/210) in ALL patients; the frequency of the CT genotype was 39% (89/228) and 29.5% (62/210), respectively; and that of the TT genotype was 53% (121/228) and 28.5% (60/210), respectively. The odds ratio was 8.4 (95% CI, 4.7-15.5; P < 0.001). These data indicate that the CYP1A1*2A genotype contributes significantly to susceptibility to adult ALL in a sample of the Mexican population.
Assuntos
Citocromo P-450 CYP1A1/genética , Predisposição Genética para Doença , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Feminino , Genótipo , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Polimorfismo Genético , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologiaAssuntos
Linfoma de Burkitt/genética , Cromossomos Humanos Par 12/genética , Cromossomos Humanos Par 21/genética , Cromossomos Humanos Par 2/genética , Translocação Genética/genética , Pré-Escolar , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Feminino , Humanos , Hibridização in Situ Fluorescente , Proteínas de Fusão Oncogênica/genética , Células Tumorais CultivadasRESUMO
A semi-quantitative expression analysis of both AML1-a and AML1-total was performed by RT-PCR in 19 children with acute lymphoblastic leukemia (ALL) at diagnosis. AML1-a expression was assessed in 16 bone marrow (BM) and 13 peripheral blood (PB) samples whereas AML1-total was assessed in 17 BM and 16 PB samples. These analyses were also carried out in 15 PB samples of healthy controls. In addition, 18/19 patients were karyotyped: 11 had an unmodified constitutional karyotype (CK) and seven exhibited acquired chromosomal abnormalities (ACA). The expression of AML1-a was significantly increased in BM and PB when compared with the controls (p < 0.013 and p < 0.035, respectively). A significant increase was found in the expression of AML1-a in BM of the ACA group compared with the CK group (p < 0.0009). The expression of AML1-a in BM and PB showed a significant increase in the ACA group compared with controls (p < 0.00001 and p < 0.012, respectively); in contrast, the CK group did not differ from the controls. These observations may mean that the increase of AML1-a favours the progression of leukemia.
Assuntos
Aberrações Cromossômicas , Proteínas de Ligação a DNA/genética , Regulação Leucêmica da Expressão Gênica , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas Proto-Oncogênicas/genética , Fatores de Transcrição/genética , Adolescente , Medula Óssea/metabolismo , Medula Óssea/patologia , Criança , Pré-Escolar , Cromossomos Humanos Par 21/genética , Subunidade alfa 2 de Fator de Ligação ao Core , Feminino , Humanos , Cariotipagem , Masculino , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
In search of a 9q13 latent centromere in 9qh polymorphic inversions: The presence of alphoid sequences in 9q13 has prompted the suggestion that such a region could harbor a latent centromere which under certain circumstances may appear as a neocentromere. We tested this hypothesis by means of FISH with a centromere 9-specific alphoid probe in lymphocyte metaphases from 13 unrelated individuals with a 9qh polymorphic inversion. Since all inverted chromosomes had the alphoid signal onto the primary constriction, it was not possible to identify any neocentromere . We believe, however, that the number of cases was not enough to conclude that all the polymorphic inversions of chromosome 9 are genuine.
Assuntos
Centrômero , Inversão Cromossômica , Cromossomos Humanos Par 9 , Polimorfismo Genético , Sequência de Bases , Marcadores Genéticos , Humanos , Hibridização in Situ FluorescenteRESUMO
A male newborn with multiple congenital abnormalities was studied. Clinically, he showed prominent forehead, facial dysmorphism, ear malformations, congenital heart defect and limb anomalies. The cytogenetic studies demonstrated a karyotype 46,XY, der(18) t(1;18)(q32;p11.3)pat with partial trisomy 1q32-qter and a monosomy 18p. The patient displayed clinical features of trisomy 1q but not of monosomy 18p. There are around 80 reports of trisomy 1q32. The purpose of this paper is to describe the first case of a translocation involving 1q and 18p chromosome breakpoints. Additional findings detected in the propositus permit us a further delineation of the trisomy 1q syndrome.
Assuntos
Anormalidades Múltiplas/genética , Cromossomos Humanos Par 1/genética , Anormalidades Craniofaciais/genética , Trissomia/genética , Deleção Cromossômica , Cromossomos Humanos Par 18/genética , Evolução Fatal , Dedos/anormalidades , Cardiopatias Congênitas/genética , Humanos , Recém-Nascido , Cariotipagem , Masculino , Anormalidades da Pele/genética , SíndromeRESUMO
A second Philadelphia (Ph) chromosome is one of the most common nonrandom secondary chromosome changes in leukemias with 9;22 translocations. It has been suggested, and observed in two studies of masked t(9;22), that the second Ph chromosome is an exact duplication of the entire derivative chromosome 22. In a cytogenetic study of bone marrow cells from an acute myelogenous leukemia patient, a cell line carrying two different Ph chromosomes evidenced by a chromosome 22 centromeric heteromorphism was found. From this observation arose the question whether the second der(22) was a true Ph chromosome or whether it was a deleted chromosome derived from the normal chromosome 22 that did not contain the bcr-abl rearrangement. A fluorescent in situ hybridization (FISH) study with the t(9;22) probe revealed two bcr-abl positive signals on 60 of 100 interphase nuclei. The second Ph could have resulted from a mitotic crossing over; or, analogously to late-appearing Philadelphia chromosomes, it may be derived from a new chromatid translocation between the chromosomes 9 and 22 not involved in the initial t(9;22).