Intronic Variants in the (rs2303426 and rs10179950) and (rs2286681 and rs62456178) Genes Are Not Associated with Colorectal Cancer in Mexican Patients.

Background/objectives: In the origin and development of colorectal cancer (CRC), a global public health problem, a dysfunction mismatch repair system appears to be a key factor. The objective was to determine the association of intronic variants in the and genes with CRC in Mexican patients.

Methods: Blood samples of 143 CRC patients and 146 reference individuals were genotyped through TaqMan Genotyping Assays.

In Silico Analysis of the Missense Variants of Uncertain Significance of Gene Reported in GnomAD Database.

pathogenic variants are related to the improper functioning of the WNT/β-catenin pathway, promoting the development of different types of cancer of somatic origin. Bioinformatics analyses of genetic variation are a great tool to understand the possible consequences of these variants on protein structure and function and their probable implication in pathologies. The objective of this study is to describe the impact of the missense variants of uncertain significance (VUS) of the gene on structure and function of the β-catenin protein.

Exon 2 Mutations in Patients with Sporadic Colorectal Cancer: Prevalence Variations in Mexican and Latin American Populations.

We searched for the prevalence of actionable somatic mutations in exon 2 of the gene in western Mexican patients with CRC. Tumor tissue DNA samples from 150 patients with sporadic CRC recruited at the Civil Hospital of Guadalajara were analyzed. Mutations in exon 2 of the gene were identified using Sanger sequencing, and the data were analyzed considering clinical-pathological characteristics.

Diagnosis of patients with Lynch syndrome lacking the Amsterdam II or Bethesda criteria.

Background: Lynch Syndrome (LS) is an autosomal dominant inheritance disorder characterized by genetic predisposition to develop cancer, caused by pathogenic variants in the genes of the mismatch repair system. Cases are detected by implementing the Amsterdam II and the revised Bethesda criteria, which are based on family history.

Main Body: Patients who meet the criteria undergo posterior tests, such as germline DNA sequencing, to confirm the diagnosis.

Microbiota composition and its impact on DNA methylation in colorectal cancer.

Colorectal cancer is a complex disease resulting from the interaction of genetics, epigenetics, and environmental factors. DNA methylation is frequently found in tumor suppressor genes to promote cancer development. Several factors are associated with changes in the DNA methylation pattern, and recently, the gastrointestinal microbiota could be associated with this epigenetic change.

Molecular Profiling of Tumor Tissue in Mexican Patients with Colorectal Cancer.

Colorectal cancer is a heterogeneous disease with multiple genomic changes that influence the clinical management of patients; thus, the search for new molecular targets remains necessary. The aim of this study was to identify genetic variants in tumor tissues from Mexican patients with colorectal cancer, using massive parallel sequencing. A total of 4813 genes were analyzed in tumoral DNA from colorectal cancer patients, using the TruSight One Sequencing panel.

Interaction of CCND2, CDKN1A, and POLD3 Variants in Mexican Patients with Colorectal Cancer.

Background: Colorectal cancer is the second cause of death by cancer around the world. Sporadic colorectal cancer is the most frequent (75%), and it is produced by the interaction of environmental, epigenetic, and genetic factors. The accumulation of single-nucleotide variants in genes associated with cell proliferation, DNA repair, and/or apoptosis could confer a risk to cancer.

High frequency of MLH1 promoter methylation mediated by gender and age in colorectal tumors from Mexican patients.

Introduction: Several genes determine the development of colorectal cancer (CRC), such as MLH1, which encodes a protein that participates in DNA repair. MLH1 hypermethylation has been associated with gene silencing.

Objective: To analyze the methylation of five regions of MLH1 CpG island in colorectal tumors from Mexican patients.

Matrix metalloproteinases 7, 8, 12, 13 gene haplotypes associated with colorectal cancer in a Mexican population.

Background: Matrix metalloproteinases (MMPs) are involved in tumor invasion and progression in colorectal cancer (CRC). Variants rs11568818, rs11225395, rs2276109 and rs2252070 have been associated with this neoplasm.

Objective: To evaluate MMPs 7, 8, 12, and 13 haplotypes and their association with CRC.

Methylation analysis of MIR200 family in Mexican patients with colorectal cancer.

The present study aimed to analyze the methylation pattern of the family in the colorectal tissues and peripheral blood of colorectal cancer (CRC) patients. Previous informed consent, 102 samples of colorectal tissues (tumor and adjacent normal tissues) and 40 peripheral blood samples were collected from CRC patients. Additionally, we included a reference group of 40 blood samples.

Somatic deletion of gene is associated to advanced colorectal cancer stages.

Aims: KDM1A/LSD1 and ZNF217 are involved in a protein complex that participates in transcriptional regulation. has been analysed in numerous cancers and its amplification has been associated with advanced stages of disease; however, a similar role for has not been uncovered. In this study, we estimated the number of and gene copies in tissue samples from patients diagnosed with colorectal cancer (CRC), as well as its association with clinicopathological features in patients with CRC.

A snapshot of current genetic testing practice in Lynch syndrome: The results of a representative survey of 33 Latin American existing centres/registries.

We aimed to assess the current genetics practice to manage patients with Lynch syndrome (LS) across Latin America. A Latin American LS survey was sent out to 52 centres/registries, comprising a total of 12 countries from the region. Overall, 33 centres completed the survey, of which the oldest LS registry was established in 1992 in Sao Paulo (Brazil), and the youngest this year in San Jose (Costa Rica).

Novel Mutations in MLH1 and MSH2 Genes in Mexican Patients with Lynch Syndrome.

Background. Lynch Syndrome (LS) is characterized by germline mutations in the DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6, and PMS2. This syndrome is inherited in an autosomal dominant pattern and is characterized by early onset colorectal cancer (CRC) and extracolonic tumors.

RUNX3 gene polymorphisms and haplotypes in Mexican patients with colorectal cancer.

We analyzed a possible association between RUNX3 gene polymorphisms and haplotypes in Mexican patients with colorectal cancer (CRC). Genomic DNA samples were obtained from the peripheral blood of 176 Mexican patients with CRC at diagnosis and from 195 individuals that formed the control group. The polymorphisms were detected by polymerase chain reaction-restriction fragment length polymorphism.

Effect of ZNF217 gene polymorphisms on colorectal cancer development in a Mexican population.

The ZNF217 gene, a potential oncogene amplified and overexpressed in several cancers including colorectal cancer (CRC), acts as a transcription factor that activates or represses target genes. The polymorphisms rs16998248 (T>A) and rs35720349 (C>T) in coronary artery disease have been associated with reduced expression of ZNF217. In this study, we analyzed the 2 polymorphisms in Mexican patients with CRC.

Association of MMP7-181A/G and MMP13-77A/G polymorphisms with colorectal cancer in a Mexican population.

Colorectal cancer (CRC) is characterized by enhanced expression and activity of several metalloproteinases (MMPs), including MMP13 and MMP7, which play an important role in tumor invasion and metastasis. The objective of this study was to analyze the association of functional MMP7-181A/G and MMP13-77A/G promoter polymorphisms with susceptibility to CRC in a Mexican population. Genomic DNA samples were obtained from peripheral blood of 102 CRC patients and 125 blood donors who were included as the control group.

MLH1 and XRCC1 polymorphisms in Mexican patients with colorectal cancer.

DNA repair proteins maintain DNA integrity; polymorphisms in genes coding for these proteins can increase susceptibility to colorectal cancer (CRC) development. We analyzed a possible association of MLH1 -93G>A and 655A>G and XRCC1 Arg194Trp and Arg399Gln polymorphisms with CRC in Mexican patients. Genomic DNA samples were obtained from peripheral blood of 108 individuals with CRC (study group) at diagnosis and 120 blood donors (control group) from Western Mexico; both groups were mestizos.

[Improvements in the diagnosis of dystrophinopathies: what have we learnt in these last 20 years?].

INTRODUCTION. Dystrophinopathies are X-linked genetic disorders caused by mutations in the DMD gene. Genetic tests are of utmost importance for management and genetic counseling of these diseases.

XRCC1 polymorphisms and haplotypes in Mexican patients with acute lymphoblastic leukemia.

We examined the influence of the Arg194Trp, Arg280His, and Arg399Gln polymorphisms of XRCC1 (X-ray repair cross-complementing group 1) on the development of childhood acute lymphoblastic leukemia (ALL) in 120 ALL patients and 120 controls in Mexico. All of them were genotyped for these polymorphisms, using polymerase chain reaction. No significant differences in allele and genotype frequencies for any polymorphism were observed between patients and controls.

A highly complex rea(2;3;11) and aniridia by position effect.

A two-year-old boy presenting with bilateral aniridia and psychomotor retardation had a de novo (2;3;11) highly complex rearrangement which was characterized as far as possible by means of G-banding and FISH assays with multiple probes including cosmids for the Wilms, Aniridia, Genital anomalies and Retardation (WAGR) region, alphoid repeats for chromosomes 2, 3 and 11, subtelomere probes for 2p/2q, 3p/3q and 11q and BACs for 2q32 and 3q13. We identified approximately 15 breakpoints with at least three interchromosomal and three intrachromosome anomalies involving chromosome 11. Both parents had normal karyotypes and no cryptic 11p rearrangements revealed by the chromosome 11 cosmid panel.

A t(1;9)(q23.3 approximately q25;q34) affecting the ABL1 gene in a biphenotypic leukemia.

Recurring chromosome translocations, which are found in leukemia, can result in the inappropriate expression of oncogenes or in the formation of chimeric genes that code for structurally and functionally abnormal proteins. The chromosomal t(1;9)(q23.3 approximately q25;q34) was found in a patient with biphenotypic leukemia.

Paternal isodisomy 7q secondary to monosomy 7 at recurrence in a Down syndrome child with acute myelogenous leukemia.

We report a boy with Down syndrome and leukemia who acquired uniparental isodisomy of chromosome 7q as a secondary chromosomal change during recurrence of the disease. His karyotype before therapy was 46,XY,der(1)t(1;1)(p36;q32),-7,+21c/46,idem,del(9)(p22), whereas at recurrence it was 46,XY,der(1)t(1;1)(p36;q32,-7,der(7)(qter-->p22 through pter::q10-->qter),del(9)(p22),+21c/47,XY,+21c. By using polymerase chain reaction amplification of D7S493 and D7S527 markers, we identified the loss of the maternal chromosome 7 with a consequent paternal isodisomy in the clone with dup7q.