Assessment of TLL1 variant and risk of hepatocellular carcinoma in Latin Americans and Europeans.

INTRODUCTION AND OBJECTIVES: Tolloid like protein 1 (TLL1) rs17047200 has been reported to be associated with HCC development and liver fibrosis. However, to our knowledge, no studies have been performed on Latin Americans and comparative differences between TLL1 rs17047200 in HCC patients from Latin America and Europe are undefined. MATERIALS AND METHODS: Cross-sectional analysis was performed on Latin American and European individuals. We analyzed TLL1 rs17047200 on DNA from 1194 individuals, including 420 patients with HCC (86.0 % cirrhotics) and 774 without HCC (65.9 % cirrhotics). RESULTS: TLL1 rs17047200 genotype AT/TT was not associated with HCC development in Latin Americans (OR: 0.699, 95 %CI 0.456-1.072, p = 0.101) or Europeans (OR: 0.736, 95 %CI 0.447-1.211, p = 0.228). TLL1 AT/TT was not correlated with fibrosis stages among metabolic dysfunction-associated steatotic liver disease (MASLD) patients from Latin America (OR: 0.975, 95 %CI 0.496-1.918, p = 0.941). Among Europeans, alcohol-related HCC had lower TLL1 AT/TT frequencies than cirrhosis (18.3 % versus 42.3 %, OR: 0.273, 95 %CI 0.096-0.773, p = 0.015). CONCLUSIONS: We found no evidence that the TLL1 rs17047200 AT/TT genotype is a risk factor for HCC development in Latin Americans or Europeans. A larger study integrating ethnic and etiology backgrounds is needed to determine the importance of the TLL1 SNP in HCC development.

Uncovering Signals of Positive Selection in Peruvian Populations from Three Ecological Regions.

Peru hosts extremely diverse ecosystems which can be broadly classified into the following three major ecoregions: the Pacific desert coast, the Andean highlands, and the Amazon rainforest. Since its initial peopling approximately 12,000 years ago, the populations inhabiting such ecoregions might have differentially adapted to their contrasting environmental pressures. Previous studies have described several candidate genes underlying adaptation to hypobaric hypoxia among Andean highlanders. However, the adaptive genetic diversity of coastal and rainforest populations has been less studied. Here, we gathered genome-wide single-nucleotide polymorphism-array data from 286 Peruvians living across the three ecoregions and analyzed signals of recent positive selection through population differentiation and haplotype-based selection scans. Among highland populations, we identify candidate genes related to cardiovascular function (TLL1, DUSP27, TBX5, PLXNA4, SGCD), to the Hypoxia-Inducible Factor pathway (TGFA, APIP), to skin pigmentation (MITF), as well as to glucose (GLIS3) and glycogen metabolism (PPP1R3C, GANC). In contrast, most signatures of adaptation in coastal and rainforest populations comprise candidate genes related to the immune system (including SIGLEC8, TRIM21, CD44, and ICAM1 in the coast; CBLB and PRDM1 in the rainforest; and BRD2, HLA-DOA, HLA-DPA1 regions in both), possibly as a result of strong pathogen-driven selection. This study identifies candidate genes related to human adaptation to the diverse environments of South America.