Case report: A familial B-acute lymphoblastic leukemia associated with a new germline pathogenic variant in PAX5. The first report in Mexico.

B-cell acute lymphoblastic leukemia (B-ALL) is one of the most common childhood cancers worldwide. Although most cases are sporadic, some familial forms, inherited as autosomal dominant traits with incomplete penetrance, have been described over the last few years. Germline pathogenic variants in transcription factors such as PAX5, IKZF1, and ETV6 have been identified as causal in familial forms. The proband was a 7-year-old Mexican girl diagnosed with high-risk B-ALL at five years and 11 months of age. Family history showed that the proband's mother had high-risk B-ALL at 16 months of age. She received chemotherapy and was discharged at nine years of age without any evidence of recurrence of leukemia. The proband's father was outside the family nucleus, but no history of leukemia or cancer was present up to the last contact with the mother. We performed exome sequencing on the proband and the proband's mother and identified the PAX5 variant NM_016734.3:c.963del: p.(Ala322LeufsTer11), located in the transactivation domain of the PAX5 protein. The variant was classified as probably pathogenic according to the ACMG criteria. To the best of our knowledge, this is the first Mexican family with an inherited increased risk of childhood B-ALL caused by a novel germline pathogenic variant of PAX5. Identifying individuals with a hereditary predisposition to cancer is essential for modern oncological practice. Individuals at high risk of leukemia would benefit from hematopoietic stem cell transplantation, but family members carrying the pathogenic variant should be excluded as hematopoietic stem cell donors.

The T29C (rs1800470) polymorphism of the transforming growth factor-ß1 (TGF-ß1) gene is associated with restenosis after coronary stenting in Mexican patients.

The aim of the present study was to establish the role of IL-6 and TGF-ß1 gene polymorphisms in the risk of developing in-stent restenosis. Two IL-6 [rs1800796 (-572 G>C), rs2069827 (-1426 T>G)] and two TGF-ß1 [rs1800469 (-509 T>C), rs1800470 (T29C)] gene polymorphisms were analyzed by 5' exonuclease TaqMan genotyping assays in a group of 244 patients, who underwent coronary artery stenting. Basal and procedure coronary angiography were analyzed, looking for angiographic predictors of restenosis and follow-up angiography was performed to screen for binary restenosis. Under the dominant and additive models adjusted for hypertension, stable angina, stent used, and diameter of stent, the TGF-ß1 T29C (rs1800470) polymorphism was significantly associated with an increase risk of restenosis when compared to patients without restenosis (OR=2.06, 95% CI: 1.03-4.11, P(Dom)=0.034 and OR=1.64, 95% CI: 1.09-2.45, PAdd=0.016). TGF-ß1 polymorphisms were in linkage disequilibrium and one haplotype (TT) was significantly increased in patients with restenosis when compared to patients without restenosis (OR=2.03, P=0.041). In summary, our results suggest that the TGF-ß1 T29C gene polymorphism could be involved in the risk of developing restenosis after coronary stent placement.

Genetic variations in toll-like receptor 4 in Mexican-Mestizo patients with intra-abdominal infection and/or pneumonia.

Sepsis is a leading cause of death around the world, and 73-83% of all sepsis cases requiring attention in intensive care units are linked to intra-abdominal infection (IAI) or pneumonia. The activation of innate immunity is central to the manifestation of sepsis, and toll-like receptor (TLR) 4 plays an important role in this activation process. The 299G and 399I alleles of TLR4 have been linked with an increased risk of Gram-negative bacteria (GNB) infections and septic shock in some populations. This case-control study evaluated the prevalence of D299G/T399I polymorphisms in Mexican patients with IAI and/or pneumonia and in healthy controls. Genotyping revealed that 1 in 44 patients (2.3%; CI 95%: 0.05-12.0%) and 4 in 126 controls (3.2%; CI 95%: 0.9-7.9%) were heterozygous for both the D299G and T399l polymorphisms (OR: 0.71, CI 95%: 0.01-7.44, p = NS), confirming the co-segregation of these alleles in this population. Furthermore, the patients with a GNB infection and severe sepsis were not carriers of the risk alleles. In summary, this report shows that the frequency of the D299G and T399I polymorphisms in Mexican-Mestizos is lower than anticipated in comparison with other ethnic groups, emphasizing the variable distribution of TLR4 polymorphisms among different populations. Consequently, this study was not able to detect associations between TLR4 polymorphisms and sepsis in this population.