RESUMEN
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.
Asunto(s)
Calpaína/genética , Diabetes Mellitus Tipo 2/genética , Predisposición Genética a la Enfermedad/genética , Polimorfismo de Nucleótido Simple , Índice de Masa Corporal , Colesterol/sangre , Diabetes Mellitus Tipo 2/sangre , Femenino , Frecuencia de los Genes , Genotipo , Haplotipos , Humanos , Desequilibrio de Ligamiento , Masculino , México , Persona de Mediana Edad , Factores de Riesgo , Triglicéridos/sangreRESUMEN
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.
Asunto(s)
Neoplasias de la Mama/genética , Carcinoma Ductal de Mama/genética , Enfermedad Fibroquística de la Mama/genética , Polimorfismo de Nucleótido Simple , Subfamilia B de Transportador de Casetes de Unión a ATP/genética , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/patología , Estudios de Casos y Controles , Femenino , Enfermedad Fibroquística de la Mama/patología , Expresión Génica , Frecuencia de los Genes , Genotipo , Humanos , México , Persona de Mediana Edad , Clasificación del Tumor , Polimorfismo de Longitud del Fragmento de RestricciónRESUMEN
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.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Neoplasias Colorrectales/genética , Proteínas de Unión al ADN/genética , Predisposición Genética a la Enfermedad , Proteínas Nucleares/genética , Polimorfismo de Nucleótido Simple/genética , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Frecuencia de los Genes/genética , Humanos , México , Persona de Mediana Edad , Homólogo 1 de la Proteína MutL , Proteína 1 de Reparación por Escisión del Grupo de Complementación Cruzada de las Lesiones por Rayos X , Adulto JovenRESUMEN
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.
Asunto(s)
Proteínas de Unión al ADN/genética , Haplotipos , Polimorfismo Genético , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Secuencia de Bases , Estudios de Casos y Controles , Niño , Preescolar , Cartilla de ADN , Electroforesis en Gel de Poliacrilamida , Femenino , Humanos , Lactante , Masculino , México , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Proteína 1 de Reparación por Escisión del Grupo de Complementación Cruzada de las Lesiones por Rayos XRESUMEN
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.
Asunto(s)
Trastornos de los Cromosomas/epidemiología , Oligospermia/genética , Aberraciones Cromosómicas , Humanos , Síndrome de Klinefelter/epidemiología , Masculino , México/epidemiología , Estudios RetrospectivosRESUMEN
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.