Forensic DNA phenotyping (FDP) is an important innovation approach in forensics sciences, especially when traditional DNA profiling results are limited, mostly due to the absence of reference samples. FDP is based on the detection of genetic variants in specific genes whose function is related to pigmentation mechanisms and uses the genotypes found in the sample to determine the externally visible traits (EVT) such as the iris, hair, and skin tone or color of the individual; this prediction would help and expedite human identification processes and solve criminal cases. Several technologies have been developed to facilitate EVT prediction; however, most of them have been validated only in European populations. Implementing techniques for FDP in Latin American countries is essential given the problems of disappearance and human identification that have persisted for years. Nonetheless, scientists have a great challenge due to the admixed genetic structure of the population. This review explores the current application of FDP, emphasizing its significance, practical uses, and limitations within Latin American populations.

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 MSH2 and PMS2 genes with CRC in Mexican patients. Methods: Blood samples of 143 CRC patients and 146 reference individuals were genotyped through TaqMan^® Genotyping Assays. Genotypic and allelic frequencies were determined by direct counting. To compare genotypic and allelic distributions, the chi-square test was used. For the association analysis, the risks of alleles and genotypes were estimated by odds ratio with 95% confidence intervals. Haplogroups were inferred with a Bayesian algorithm. Linkage disequilibrium was measured using D’ and r² with Arlequin v3.5.2. The in silico analysis was carried out using the SpliceAI, UCSC, JASPAR and TRRUST platforms. All statistical analyses were performed with SPSS v29.0.2.0. Results: In the CRC group, the mean age was 58.2 ± 14.7 years and 60.8% were men. No variant was associated with CRC or implicated in gene post-replicative processing. Linkage disequilibrium was observed for loci rs2303426 and rs10179950 in MSH2 and for loci rs2286681 and rs62456178 in PMS2. Conclusions: The genotypic and allelic frequencies of the four variants are reported for the first time in Mexican patients with CRC. No association was found between gene variants and risk for CRC but there was a strong linkage disequilibrium between the loci of both MSH2 and PMS2 genes. None of the variants showed a possible repercussion on splicing.

El cáncer oral en México, se ubica en el lugar 21 en incidencia y 24 en mortalidad, sin embargo, cada década su incidencia aumenta debido a la exposición a factores de riesgo que han sido asociados a esta neoplasia: consumo de tabaco y alcohol, exposiciones virales y eventos genéticos específicos dentro de los que destacan la presencia de la variante c.-93G>A y la metilación del gen MLH1, por lo que el objetivo de la presente revisión se centra en describir el impacto de estos dos eventos en el desarrollo de cáncer oral de células escamosas (COCE). Se ha propuesto que la SNV c.-93G>A en el gen MLH1 puede estar relacionada con alteraciones en la tasa transcripcional, además de asociarse con el riesgo y pronóstico del COCE, mientras que la metilación se ha asociado con una disminución e incluso supresión de la expresión proteica. Ambas alteraciones repercuten sobre la expresión de la proteína, afectado el proceso de reparación del DNA y al ser parte esencial de fisiopatología es relevante realizar el análisis de la variante c.-93 G>A y la metilación del gen MLH1 en pacientes con carcinoma oral de células escamosas. DOI: https://doi.org/10.54167/tch.v17i2.1194