ABSTRACT
En vista de la alta prevalencia del cáncer de próstata en la población venezolana y la ausencia de un patrón genético conocido en relación a la expresión de las enzimas Glutatión S-transferasas, se estudió la relación entre la expresión de un polimorfismo nulo de estas enzimas y la presencia de cáncer de adenocarcinoma prostática Métodos: Se incluyen 100 individuos para el muestreo no probabilístico, 50 pacientes con diagnóstico de adenocarcinoma de próstata comprobado mediante biopsia y 50 controles con hiperplasia prostática benigna demostrada mediante tacto y corroborada por ultrasonido transrectal, provenientes de los principales hospitales del país, se procedió a tomar muestra de sangre y mediante reacción de cadena de polimerasa, se determinó la presencia o ausencia de los genes para las enzimas Glutatión S-transferasa Mu 1 (GST M) y glutatión S-transferasa theta 1 (GST T1). Resultados: se logró evidenciar que el genotipo nulo se encontró en 40 y 24% de los pacientes mientras que para los controles fue de 38% y 22% respectivamente, demostrando que en la población venezolana estudiada no existen diferencias significativas entre casos y controles. Conclusiones: No se pudo demostrar una diferencia significativa entre los dos grupos estudiados. Recomendaciones: A pesar de nuestros hallazgos, se necesitan estudios futuros con muestras de mayor tamaño para dilucidar la posible asociación entre este patrón enzimático con el riesgo de presentar cáncer de próstata(AU)
Prostate cancer presents with a high incidence in the Venezuelan population. there is no known genetic pattern related to the expression of drug metabolizing enzymes Glutathione S-transferases. Methods: We proceeded to study the possible correlation between null polymorphism for these enzymes and prostate adenocarcinoma. the sample included 100 patients recruited from the Urology Department of three University Hospitals in Caracas, Venezuela, 50 cancer patients and 50 cancer free controls. Blood samples were drawn from each patient and polymorphisms for Glutathione S-transferase Mu 1 (GST M1) and Glutathione-sS-transferase theta 1(GST T1) were determined by polymerase chain reaction from lymphocytes. Results: Null genotype was found in 40% and 24% of cancer patients whereas the percentage in controls was 38 and 22% respectively, showing no statistically significant differences between the two groups. Conclusions: It was not possible to show a significant difference between the two groups. Recommendations: Due to the small size of the sample, it would be necessary to explore further in a larger population sample to determine whether there is an association between the expression of these enzymes and prostate cancer(AU)
Subject(s)
Humans , Male , Prostatic Hyperplasia/diagnosis , Prostatic Neoplasms/enzymology , Prostatic Neoplasms/pathology , Prostate-Specific Antigen , Ultrasound, High-Intensity Focused, Transrectal/methods , Glutathione TransferaseABSTRACT
In order to establish the spectrum of ß-thalassemia (ß-thal) mutations in the Venezuelan population for the first time, 127 unrelated subjects either with a suspicion of ß-thal trait or with a clinically recognized ß-thal syndrome of different degrees of severity, were studied. DNA from these subjects was analyzed by a polymerase chain reaction (PCR)-based reverse dot-blot method or amplification refractory mutation system (ARMS). Prototype ß-globin gene sequencing of relevant DNA was performed to confirm the mutations. Fifteen different mutations were identified accounting for 92.0% of the mutant alleles explored, revealing a significant genetic heterogeneity at the ß-globin gene locus in this population. The most frequent mutations were codon 39 (C >T) 34.1%, IVS-I-1 (G >A) 11.1%, IVS-I-6 (T > C) 6.6%, IVS-I-110 (G >A) 6.6%, IVS-II-849 (A >G) 6.6%, -88 (C >T) 6.0%, -29 (A >G) 5.2%, followed by the less common IVS-I-5 (G >A) 3.7%, the 1,393 bp deletion 3.0%, IVS-II-1 (G >A) 3.0%, -86 (C >G) 2.2%, IVS-II-1 (G >T) 1.5%, codons 41/42 (-TCTT) 1.5%, IVS-II-745 (C >G) 0.7% and deletional δß-thal 0.7%. Overall, these data demonstrate that the major sources of ß-thal alleles in Venezuela, as expected, are of Mediterranean and African origins. This is the first large study defining the molecular spectrum of ß-thal in the highly admixed population of Venezuela and lays the foundation for genetic counseling as well as implementing comprehensive clinical care programs. Diversity of haplotypes associated with some of the ß-thal mutations can be explained by in situ recombination events in Venezuela.
Subject(s)
Haplotypes , Mutation , beta-Globins/genetics , beta-Thalassemia/genetics , Base Sequence , DNA Mutational Analysis , Gene Frequency , Genotype , Humans , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Prevalence , Venezuela/epidemiology , beta-Thalassemia/epidemiologyABSTRACT
BACKGROUND: Several previous studies reported that the Venezuelan Warao Indians presented unusual genetic characteristics. AIM: The present study checked previous reports of a high frequency of hereditary persistence of fetal hemoglobin (HPFH) and examined other hematological traits. SUBJECTS AND METHODS: Standard hematology, electrophoresis on cellulose acetate, fetal hemoglobin alkali denaturation, gamma-globin chain, DNA amplification and sequencing, and denaturing gradient gel electrophoresis determinations were performed in 269 individuals living in two localities of the Orinoco River Delta. RESULTS: Two beta(s) genes, in apparently non-related individuals, were found. HPFH, detected in this same population of Warao Indians 25 years ago, was present in heterozygous form in five individuals from a large kindred, with hemoglobin F levels ranging from 3.7% to 8%, and with a pancellular distribution. The HPFH mutation was of the deletional type. beta-globin gene haplotypes were determined by direct counting (through family studies) in 150 chromosomes; 26% of the 150 examined cluster presented haplotype 2, 22% haplotype 6, and 13% a new, Warao haplotype. Haplotype 3, of probable African origin, was also found with a frequency of 5%. CONCLUSIONS: The presence of the HPFH mutation was confirmed, and the new beta-globin gene haplotype together with the presence of other rare variants indicates that the Warao are very distinctive in relation to other Native Americans. Evidence was also found of a slight admixture from Africa-derived subjects (Layrisse et al. 1988).
Subject(s)
Globins/genetics , Haplotypes , Hemoglobins, Abnormal/analysis , Indians, South American/genetics , Alleles , Black People/genetics , Child , Chromosome Mapping , Female , Fetal Hemoglobin/analysis , Fetal Hemoglobin/genetics , Gene Frequency , Gene Pool , Globins/analysis , Hemoglobins, Abnormal/genetics , Heterozygote , Humans , Male , Pedigree , Population Groups/genetics , Sequence Deletion , VenezuelaABSTRACT
Entre las hemoglobinopatías, grupo heterogéneo de alteraciones congénitas, destacan: las variantes de hemoglobina, las talasemias y la persistencia hereditaria de hemoglobina fetal (HPFH). Se determinó la distribución de estas patologías en Venezuela y se demostró que presentan una elevada frecuencia, constituyendo un problema de salud pública. Se analizaron 80400 individuos provenientes de estudios poblacionales de diferentes regiones del país y pacientes referidos por presentar anemia hemolítica fueron referidos a dos centros de investigación hematológica. Fueron estudiadas 76400 muestras mediante electroforesis en acetato de celulosa y en citrato agar y 4000 por cromatografía líquida de alta presión de intercambio catiónico (HPLC-CE). Se encontró que el 9 por ciento de los individuos presentaron hemoglobinopatías. La variante más frecuente fue la Hb S, seguida de las variantes C y D. Además, se observó la presencia de la beta talasemia y su asociación a las hemoglobinas S y C. La frecuencia de los haplotipos del gen bs estudiados en 272 de pacientes con síndrome drepanocítico (SCA) y heterocigotos para la Hb S fue de 50,8 por ciento Benin, 32,2 por ciento CAR, 14,2 por ciento Senegal y 2,3 por ciento Camerún. Se encontró que en los pacientes homocigotos para la Hb S estudiados, solo el 8 por ciento fue homocigoto para el haplotipo Ben, 82 por ciento fueron doble heterocigotos para los haplotipos Ben/CAR, 8,8 por ciento presentaron haplotipos Ben/Senegal, CAR/Senegal y Ben/Camerún y un caso fue homocigoto para el haplotipo CAR. La detección de estas patologías es de importancia para establecer un tratamiento precoz y consejo genético, logrando una mejor calidad de vida y gran ahorro para el sistema de salud.
