Sickle Cell Mexican

Hemoglobin S is caused by a nucleotide change in HBB gene (HBB:c.20A>T, p.Glu6Val), is presented in diverse forms: simple carriers (HbSA), homozygotes (HbSS) also known as sickle cell anemia, and compound heterozygotes with other β-hemoglobinopathies. It is worldwide distributed, in Mexico, is frequently observed in the southern states Guerrero, Oaxaca and Chiapas. Elevated fetal hemoglobin (HbF) is associated with mild phenotype; single-nucleotide variants (SNVs) in modifier genes, such as BCL11A, HBG2, HBBP1 pseudogene and HBS1L-MYB intergenic region, upregulate HbF synthesis...

Mexicans are a recent admixture of Amerindians, Europeans, and Africans. We performed local ancestry analysis of Mexican samples from two genome-wide association studies obtained from dbGaP, and discovered that at the MHC region Mexicans have excessive African ancestral alleles compared to the rest of the genome, which is the hallmark of recent selection for admixed samples. The estimated selection coefficients are 0.05 and 0.07 for two datasets, which put our finding among the strongest known selections observed in humans, namely, lactase selection in northern Europeans and sickle-cell trait in Africans...

Between 1978 and 2009, we studied 1,863 Mexican Mestizo patients with clinical data compatible with a hemoglobinopathy. Of these patients, 382 had some hemoglobin (Hb) abnormality (20.5%), 128 had a sickle cell hemoglobinopathy, representing a general frequency of 6.9%, which is similar to the percentage observed in previous studies on Mexican Mestizos. We analyzed the 5' β-globin haplotype (5'Hp) in 79 unrelated β(S) chromosomes (26 β(S)/β(S), 14 β(S)/β(Thal), nine β(S)/β(A) and four β(S)/β(D)), and four haplotypes were observed: 72...

The aim of this study was to determine the frequency of alpha-globin gene mutations in three groups of Mexican unrelated individuals. The first two groups were normal and sickle cell trait individuals from the Costa Chica region, a place with a 12.8% frequency of HbS carriers, and the third group comprised of Mexican mestizo patients with beta-thalassemia. We searched for -alpha(3.7) and -alpha(4.2) alpha(+)-thalassemia deletion alleles, as well as the alpha alpha alpha(anti3.7) triplication through long-gap PCR...

The beta-globin gene cluster has shown high polymorphic diversity organized in 5' and 3' haplotypes (Hps). beta(S)-Chromosomes are in linkage disequilibrium with the 5' Hps Bantu, Benin, Senegal, Cameroon, and Arab-Indian. In Mexican mestizos with African west coast origins, we observed the following 5' Hps in beta(S)-chromosomes: Bantu, 78.8%; Benin, 18.2%; and atypical Hp 9, 3.0%. With the purpose of establishing the 3' Hps, we analyzed 35 polymorphic sites--6 by RFLP analysis and 29 by DNA sequencing--in 33 unrelated beta(S)-chromosomes...

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To investigate the origin of the beta(A) and beta(S) genes in a Mexican population with African roots and a high frequency of hemoglobin S, we analyzed 467 individuals (288 unrelated) from different towns in the states of Guerrero and Oaxaca in the Costa Chica region. The frequency of the sickle-cell trait was 12.8%, which may represent a public health problem. The frequencies of the beta-haplotypes were determined from 350 nonrelated chromosomes (313 beta(A) and 37 beta(S)). We observed 15 different beta(A) haplotypes, the most common of which were haplotypes 1 (48...

BACKGROUND: The prevalence of beta-thalassemia in Mexico is not known in detail. METHODS: Data of studies investigating abnormal hemoglobins between September 1987 and November 2000 were analyzed; in addition, data of red-blood-cell indices and clinical features were analyzed in patients identified as carriers of beta-thalassemia. RESULTS: In 1,639 prospective studies looking for abnormal hemoglobins, 429 disclosed some abnormality; of these, 319 cases displayed abnormally high levels of hemoglobin A2, thus consistent with the diagnosis of beta-thalassemia...

No abstract text is available yet for this article.

Molecular studies using polymerase chain reaction (PCR) and restriction enzymes, as well as intragenic STRs and newly designed primers, were performed in patients with Duchenne-Becker muscular dystrophy, sickle cell anemia, retinoblastoma, and nephroblastoma. The usefulness of these methodologies in the precise identification of mutational changes, in carrier detection and in the understanding of neoplastic transformations, as well as its applications in genetic counseling and prenatal diagnosis, are discussed...

Cord blood samples from 29,611 infants born in Los Angeles over a 71/2 year period were examined for hemoglobinopathies. Among 4,134 Black newborns, the frequency of sickle cell anemia (SS) was 0.3 per cent, of sickle cell trait (AS) 8 per cent, and of Hb-C trait (AC) 2 per cent. Of 17,781 Spanish surnamed (Mexican) newborns, 0.5 per cent had sickle cell trait, and 0.1 per cent had Hb-C trait. Of the 5,541 Caucasian infants, 0.7 per cent had sickle cell trait, and 0.15 per cent had Hb-C trait. Twenty-three Black children with major hemoglobinopathies included 16 with sickle cell anemia, two with hemoglobin C disease (CC), and five with SC disease...

Sickle cell (drepanocytic) anemia is a hereditary blood disease occurring very rarely in Mexico. A 13-year-old Mexican boy with sickle cell anemia eventually died of a cerebrovascular accident of the brain stem, as shown by computerized tomography (CT). A characteristic moyamoya-like angiographic pattern was demonstrated on bilateral carotid and left vertebral arteriograms. Moyamoya disease has no known etiology, but the characteristic angiographic features of moyamoya have been observed in conjunction with some other disease of known origin (including sickle cell anemia)...

A 5-year-old Mexican-American boy developed marked elevation of intraocular pressure in association with a small traumatic hyphema. Laboratory studies prompted by this clinical presentation revealed that the child had sickle trait. Pressure returned to normal after surgical evacuation of blood from the anterior chamber. Sickle cell hemoglobinopathy should be considered in the differential diagnosis of secondary glaucoma following blunt ocular trauma even in non-black patients.