RESUMO
The calpain-10 gene is expressed primarily in tissues important in glucose metabolism; thus, some of its polymorphisms have been associated with type 2 diabetes. In this study, we examined the association between the calpain-10 single-nucleotide polymorphism (SNP)-43, SNP-19, and SNP-63 and type 2 diabetes in Mexican mestizos. We included 211 patients and 152 non-diabetic subjects. Polymerase chain reaction was used to identify alleles. We compared allele, genotype, haplotype, and diplotype frequencies between both groups and used the chi-square test to calculate the risk. The allele frequency of SNP-43 allele 1 was 70% in controls and 72% in patients; the GG, GA, and AA genotype frequencies were 48.7, 42.8, and 8.5% in controls and 51.2, 41.7, and 7.1% in patients, respectively. For SNP- 19, the prevalence of allele 1 (2R) was 32% in controls and 39% in patients. In controls, homozygosity (2R/2R) was 10.5%, heterozygosity was 42.8%, and 3R/3R was 46.7%; in cases, these values were 13.3, 50.7, and 36.0%, respectively. For SNP-63, the frequency of allele 1 was 87% in controls and 83% in patients; genotype frequencies in controls were 75.7% (CC), 23% (CT), and 1.3% (TT), and were 69.7, 27.5, and 2.8%, respectively for the cases. Genotype distributions were consistent with Hardy-Weinberg equilibrium. No significant intergroup differences for allele, genotype, haplotype, or diplotype frequencies were observed. We found no association between these polymorphisms and diabetes. However, our sample size was small, so the role of calpain-10 risk alleles should be further examined.
Assuntos
Calpaína/genética , Diabetes Mellitus Tipo 2/genética , Predisposição Genética para Doença/genética , Polimorfismo de Nucleotídeo Único , Índice de Massa Corporal , Colesterol/sangue , Diabetes Mellitus Tipo 2/sangue , Feminino , Frequência do Gene , Genótipo , Haplótipos , Humanos , Desequilíbrio de Ligação , Masculino , México , Pessoa de Meia-Idade , Fatores de Risco , Triglicerídeos/sangueRESUMO
We investigated whether the MDR1 C3435T polymorphism is associated with fibrocystic changes (FCC), infiltrating ductal breast cancer (IDBC), and/or clinical-pathological features of IDBC in Mexican patients. Samples from women who received surgical treatment in 2007 at the Centro Médico de Occidente (México) were included in the analysis. Genotyping was performed by polymerase chain reaction-restricted fragment length polymorphisms in 64 paraffin-embedded breast samples with IDBC, 64 samples with FCC, and 183 peripheral blood samples of healthy females designated as the healthy group (HG). The frequency of the T allele was 41, 45, and 52% for the FCC, IDBC, and HG samples, respectively. Significant differences were only found between the FCC and HG samples [odds ratio (OR) = 0.64, 95% confidence interval (CI) = 0.43-0.96; P = 0.032]. The prevalence of the T/T genotype was 8, 13, and 24% for FCC, IDBC, and HG samples, respectively. Again, statistical differences were only found between FCC and HG samples for the T/T genotype (OR = 0.28, 95%CI = 0.106-0.77; P = 0.009). Although the T allele and the T/T genotype were less frequent in the IDBC group than in the HG, the differences were not significant. Furthermore, no associations were found between the C3435T polymorphism and clinical-pathological features of the IDBC group. Both the FCC and IDBC groups had a high frequency of the C allele relative to the HG in this sample of women from Western Mexico.
Assuntos
Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Doença da Mama Fibrocística/genética , Polimorfismo de Nucleotídeo Único , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Estudos de Casos e Controles , Feminino , Doença da Mama Fibrocística/patologia , Expressão Gênica , Frequência do Gene , Genótipo , Humanos , México , Pessoa de Meia-Idade , Gradação de Tumores , Polimorfismo de Fragmento de RestriçãoRESUMO
DNA repair proteins maintain DNA integrity; polymorphisms in genes coding for these proteins can increase susceptibility to colorectal cancer (CRC) development. We analyzed a possible association of MLH1 -93G>A and 655A>G and XRCC1 Arg194Trp and Arg399Gln polymorphisms with CRC in Mexican patients. Genomic DNA samples were obtained from peripheral blood of 108 individuals with CRC (study group) at diagnosis and 120 blood donors (control group) from Western Mexico; both groups were mestizos. The polymorphisms were detected by PCR-RFLP. Association was estimated by calculating the odds ratio (OR). We found that the MLH1 and XRCC1 polymorphisms were in Hardy- Weinberg equilibrium. The MLH1 655A>G polymorphism in the 655G allele was associated with a 2-fold increase risk for CRC (OR = 2.04 and 95% confidence interval (95%CI) = 1.12-3.69; P < 0.01), while the MLH1 -93G>A polymorphism allele was associated with a protective effect (OR = 0.60, 95%CI = 0.40-0.89; P = 0.01 in the -93A allele and OR = 0.32, 95%CI = 0.13-0.79; P = 0.01 in the AA genotype). The XRCC1 Arg194Trp and Arg399Gln polymorphisms did not show any significant associations. In conclusion, we found that MLH1 -93G>A and 655A>G polymorphisms are associated with CRC in Mexican patients.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Neoplasias Colorretais/genética , Proteínas de Ligação a DNA/genética , Predisposição Genética para Doença , Proteínas Nucleares/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Frequência do Gene/genética , Humanos , México , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Proteína 1 Complementadora Cruzada de Reparo de Raio-X , Adulto JovemRESUMO
We examined the influence of the Arg194Trp, Arg280His, and Arg399Gln polymorphisms of XRCC1 (X-ray repair cross-complementing group 1) on the development of childhood acute lymphoblastic leukemia (ALL) in 120 ALL patients and 120 controls in Mexico. All of them were genotyped for these polymorphisms, using polymerase chain reaction. No significant differences in allele and genotype frequencies for any polymorphism were observed between patients and controls. Estimation of haplotypes showed the eight expected haplotypes (A-H), seven of which were found in both patients and controls; haplotype A (Arg-Arg-Arg) was the most common, whereas haplotypes F and G were absent in patients and controls, respectively. Haplotype B (Trp-Arg-Arg) was found to be associated with an increased risk of ALL (odds ratio (OR) = 1.95, 95% confidence interval (CI) = 1.13-3.37; P = 0.016), particularly in males (OR = 2.65, 95%CI = 1.25-5.63; P = 0.01). Individually, the 194Trp, 280His, and 399Gln alleles were not associated with significantly increased risk for ALL in these Mexican children.
Assuntos
Proteínas de Ligação a DNA/genética , Haplótipos , Polimorfismo Genético , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Sequência de Bases , Estudos de Casos e Controles , Criança , Pré-Escolar , Primers do DNA , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Lactente , Masculino , México , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Proteína 1 Complementadora Cruzada de Reparo de Raio-XAssuntos
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
In order to assess the frequency of chromosomal abnormalities in azoospermic males from western Mexico, we carried out a retrospective study in 227 patients. Forty-three (18.9%) cases with an abnormal karyotype were found. The most frequent chromosomal anomaly was 47,XXY, which was identified in 35 subjects (15.4%). In six cases (2.6%), structural aberrations were detected: two Robertsonian translocations [(45,XY,t(13;22)(p11;p11) and (45,XY,t(13;15)(p11;p11)], a Y;autosome translocation [46,XY,der(15)t(Y;15)(q12;p11)], and three mosaics [mos45,X/46,X,idic(Y)(q11)]. In general, these findings are in accordance with those from other surveys and confirm that the XXY aneuploidy is the most frequent chromosomal abnormality in azoospermic individuals.
Assuntos
Transtornos Cromossômicos/epidemiologia , Oligospermia/genética , Aberrações Cromossômicas , Humanos , Síndrome de Klinefelter/epidemiologia , Masculino , México/epidemiologia , Estudos RetrospectivosRESUMO
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
We report a boy with Down syndrome and leukemia who acquired uniparental isodisomy of chromosome 7q as a secondary chromosomal change during recurrence of the disease. His karyotype before therapy was 46,XY,der(1)t(1;1)(p36;q32),-7,+21c/46,idem,del(9)(p22), whereas at recurrence it was 46,XY,der(1)t(1;1)(p36;q32,-7,der(7)(qter-->p22 through pter::q10-->qter),del(9)(p22),+21c/47,XY,+21c. By using polymerase chain reaction amplification of D7S493 and D7S527 markers, we identified the loss of the maternal chromosome 7 with a consequent paternal isodisomy in the clone with dup7q. This rearrangement could be implicated in the progression of the disease by causing (1) nullisomy for a gene or genes located on 7p22-->pter, (2) functional double doses of exclusively paternal expressed genes, and (3) restoration of the effects produced by haploinsufficiency of biparental expressed genes.
