Variantes alélicas de CYP2D6: *4, *6 y *10 en una muestra de residentes del estado Aragua, Venezuela / Allelic variants of the CYP2D6: *4, *6 and *10 in a sample of resident from the Aragua state, Venezuela

El objetivo del estudio fue determinar la frecuencia de las variantes del gen CYP2D6: *4, *6 y *10 y predecir el fenotipo metabolizador en una muestra de 145 individuos no consanguíneos, aparentemente sanos, residentes del estado Aragua, Venezuela. Los genotipos fueron determinados mediante ensayos de reacción en cadena de la polimerasa seguidos de digestión con endonucleasas de restricción. La predicción del fenotipo metabolizador se realizó con base al sistema Activity score. Las frecuencias de CYP2D6 *4, *6 y *10 fueron de 14,5%, 0,3% y 1%, respectivamente; un porcentaje significativo de individuos fueron categorizados como metabolizador rápido heterocigoto/metabolizador intermedio (23,5%) y metabolizador lento (4,1%). Esta información tiene impacto clínico potencial, porque CYP2D6 interviene en el metabolismo de fármacos de prescripción frecuente como: carvedilol, captopril, cloroquina, codeína, fluoxetina, fluvastatina, haloperidol, idarrubicina, indinavir, imatinib, loperamida, nifedipina, ondansetrón y tamoxifeno...

The aim of this study was to determine the CYP2D6: * 4, * 6 and * 10 gene variants frequency and to predict the metabolizer phenotype in a sample of 145 unrelated apparently healthy individuals residing in the state of Aragua, Venezuela. Genotypes were determined by Polymerase chain reaction assays followed by restriction endonucleases digestion. The metabolizer phenotype prediction was made based on the activity score system. The frequencies of CYP2D6 * 4, * 6 and * 10 allelic variants were 14.5%, 0.3% and 1%. A significant percentage of individuals were categorized as heterozygote-extensive/intermediate (23.5%) and poor metabolizers (4.1%), this information has potential clinical impact, because the CYP2D6 protein is involved in the metabolism of drugs frequently prescribed as: carvedilol, captopril, chloroquine, codeine, fluoxetine, fluvastatin, haloperidol, idarubicin, indinavir, imatinib, loperamide, nifedipine, ondansetron and tamoxifen...

Alteraciones de la diferenciación sexual en pacientes de las regiones Capital y centro occidental de Venezuela / Disorders of sexual differentiation in patiens from the capital and west Center Regions of Venezuela

Las alteraciones de la diferenciación sexual (ADS) son patologías originadas por trastornos en una de las tres etapas sucesivas de dicha diferenciación: cromosómica (XX, XY), gonadal (testículo, ovario) o fenotípica. El objetivo del trabajo fue dar a conocer la forma de presentación de las ADS en pacientes provenientes de las regiones Capital y Centro Occidental de Venezuela. Se incluyeron diecisiete pacientes y se elaboraron los árboles genealógicos, se realizó evaluación clínica, estudios hormonales, citogenéticos, imagenología y determinación de marcadores del gen SRY y microsatélites del cromosoma Y. En función de la evaluación clínica y los datos obtenidos de los exámenes practicados, se efectuaron los diagnósticos siguientes: a) Doce corresponden a ADS 46,XX , de los cuales siete pacientes tienen ADS por exceso de andrógenos, un caso con reversión sexual, un ADS ovotesticular, un caso con síndrome malformativo, uno con disgenesia gonadal y uno con hipogonadismo, b) Cuatro presentan ADS 46,XY (un paciente con síndrome de Smith-Lemli-Opitz II, uno con síndrome malformativo y dos casos con hipogonadísmo), c) Un caso de ADS por alteración cromosómica 46,XXY (síndrome de Klinefelter). En relación a la edad de la primera consulta, la mayor parte (47,1%) se realizó en menores de 5 años, referidos por ambigüedad sexual con necesidad de resolver la identificación del sexo; en la pubertad los pacientes consultan por alteraciones en los caracteres sexuales secundarios y amenorrea (adolescentes); en la adultez por infertilidad. Los resultados permitieron realizar un mejor asesoramiento genético y contribuir a mejorar la calidad de vida de los pacientes y sus grupos familiares.

Disorders of sexual differentiation (DSD) are pathologies characterized by an atypical development of chromosomal (XX, XY) gonadal (testis, ovary) or phenotypical sex. The objective of this work was to inform the presentation forms of SDS in patients from the Capital and West Center regions of Venezuela. Seventeen patients were included and the pedigrees, clinical evaluation, hormonal studies, cytogenetic, imaging and identification of SRY gene markers and Y chromosome microsatellites were made. Depending on the clinical evaluation and data from examinations carried out, the following diagnoses were made: a)Twelve patients correspond to DSD 46, XX, of which seven patients have DSD by androgen excess, a case with sex reversal a ovotesticular DSD, a case with malformation syndrome, one with gonadal dysgenesis and one hypogonadism; b) Four patients presented DSD 46, XY (a patient with Smith-Lemli-Opitz syndrome II, one malformation syndrome and two cases with hypogonadism) c) A case of ADSs by chromosomal abnormality 46,XXY (Klinefelter syndrome). In relation to age of first consultation, the majority (47.1%) was performed in children under 5 years, referred by sexual ambiguity with need to address sex identification. In puberty, the patients consult due to alterations in secondary sexual characteristics and amenorrhea in teenagers, in adulthood due to infertility. The results helped to make a better genetic counseling and to improve the quality of life of patients and their families.

Frequency of CCR5 delta-32 mutation in human immunodeficiency virus (HIV)-seropositive and HIV-exposed seronegative individuals and in general population of Medellin, Colombia

Repeated exposure to human immunodeficiency virus (HIV) does not always result in seroconversion. Modifications in coreceptors for HIV entrance to target cells are one of the factors that block the infection. We studied the frequency of Delta-32 mutation in ccr5 gene in Medellin, Colombia. Two hundred and eighteen individuals distributed in three different groups were analyzed for Delta-32 mutation in ccr5 gene by polymerase chain reaction (PCR): 29 HIV seropositive (SP), 39 exposed seronegative (ESN) and 150 individuals as a general population sample (GPS). The frequency of the Delta-32 mutant allele was 3.8 for ESN, 2.7 for GPS and 1.7 for SP. Only one homozygous mutant genotype (Delta-32/Delta-32) was found among the ESN (2.6). The heterozygous genotype (ccr5/Delta-32) was found in eight GPS (5.3), in one SP (3.4) and in one ESN (2.6). The differences in the allelic and genotypic frequencies among the three groups were not statistically significant. A comparison between the expected and the observed genotypic frequencies showed that these frequencies were significantly different for the ESN group, which indirectly suggests a protective effect of the mutant genotype (Delta-32/Delta-32). Since this mutant genotype explained the resistance of infection in only one of our ESN persons, different mechanisms of protection must be playing a more important role in this population.