Biomedical subjects

Norma Olivares

Publications and source records attributed to Norma Olivares.

4 recordsLinked to original sources

PubMed2004

HLA class II haplotypes in Mexican systemic lupus erythematosus patients.

Systemic lupus erythematosus (SLE) is an autoimmune disease in which polymorphisms within the human leukocyte antigen (HLA) region have been associated to its etiology. For this study, HLA-DQB1, DQA1, and DRB1 genes were typed by polymerase chain reaction-sequence-specific primer in 237 individuals, taken from 74 families, who had a member with SLE, and who had their residence in the western region of Mexico; as well as in 159 ethnically matched healthy volunteers taken from 32 families. Genotype and allele frequency analysis was performed in 74 SLE patients and 54 unrelated controls. Precise three-loci identification of independent haplotypes was performed in 48 patients and 54 controls by familial segregation. Genotype distribution at each loci was concordant with Hardy-Weinberg's equilibrium in the control group. In general, no genotype effect was observed in SLE patients. Allele distribution comparison showed in the SLE group a significant increase of HLA-DQA1*0102, DQB1*0402, and DRB1*15; whereas alleles HLA-DQB1*0303 and *0501 were significantly decreased. SLE patients showed haplotype DQB1*0602-DQA1-*0102-DRB1*15 increased. As expected, patients with SLE have a reduced haplotype genetic diversity. The associations found in this study are related to an ancestral haplotype that has been observed in SLE populations of different origins.

Adolescent↗

PubMedDate not supplied

Thrombophilic polymorphisms in preterm delivery.

Single nucleotide polymorphisms tumor necrosis factor (TNF) G-308A, coagulation factors V G1691A and II G20210A, methylenetetrahydrofolate reductase (MTHFR) C677T, as well as the angiotensin-converting enzyme (ACE) insertion/deletion polymorphism were investigated in 86 women with a history of premature delivery (PD) and compared with those of a control group of adults from Guadalajara, Mexico (a minimum of 162 individuals were typed for each polymorphism). Significant differences in the frequency of these polymorphisms were found for MTHFR C677T (increased), and the ACE deletion (increased) among women who had a history of preterm delivery compared with controls. These polymorphisms therefore might be associated with PD.

Adolescent↗

PubMedDate not supplied

[Assessment of five thrombophilic genetic polymorphisms among couples with habitual abortion].

An association between thrombophilic genes and obstetric conditions with early pregnancy termination has been previously proposed. In the present study we attempted to evaluate the possible association between thrombophilic genetic polymorphisms and habitual abortion (HA). Samples from two groups of volunteers were analyzed. The experimental group (n>100) was conformed by women attending the Centro Medico de Occidente, IMSS and their male couples, with a reproductive history ofat least three miscarriages. The reference group (n > 200) was composed by male and female healthy adults living in the state of Jalisco, Mexico. DNA was extracted from peripheral blood, and polymorphisms FII G20210A , FVG1691A, MTHFR C677T, ECA IID y TNF G-308A were typed by PCR-RFLP or -SSP. Genotype proportions in the reference group were in agreement with the HardyWeinberg expectations. Allele, genotype, and phenotype proportion inter-group comparisons did not show statistically significant differences. The present results could not demonstrate that thrombophilic polymorphisms constitute risk factors for HA in Jalisco.

Abortion, Habitual↗

PubMedDate not supplied

[Meiotic and parental origin of extra chromosome 21 in children with regular trisomy 21].

INTRODUCTION: Down syndrome (DS) or trisomy 21 is the most common chromosomal abnormality in live birth children. Most cases are regular trisomies 21 secondary to a maternal non-disjunction (ND). Meiotic and parental origins have been recently investigated by segregating genetic markers from DNA hypervariable regions. OBJECTIVE: To identify the meiotic and parental origin in children with regular trisomy 21. MATERIALS AND METHODS: There were analyze 20 groups of three (every group included parents and child with Down syndrome). There were used soothe following markers: D21S11, D21S1260, and D21S265. RESULTS: The ND occurred during the first meiotic division (M1) in 13 cases and at the second meiotic division (M2) in the other seven. Twelve out of the 13 NDs from the first group were maternal and one paternal. The parental origin within the M2 group was not elucidated. CONCLUSIONS: Meiotic origin was identified in all cases. As in other reports, the origin of trisomy 21 in the present population is mainly secondary to a maternal ND in M1.

Child↗