The multifaceted genomic history of Ashaninka from Amazonian Peru.

Despite its crucial location, the western side of Amazonia between the Andes and the source(s) of the Amazon River is still understudied from a genomic and archaeogenomic point of view, albeit possibly harboring essential information to clarify the complex genetic history of local Indigenous groups and their interactions with nearby regions,1,2,3,4,5,6,7,8 including central America and the Caribbean.9,10,11,12 Focusing on this key region, we analyzed the genome-wide profiles of 51 Ashaninka individuals from Amazonian Peru, observing an unexpected extent of genomic variation. We identified at least two Ashaninka subgroups with distinctive genomic makeups, which were differentially shaped by the degree and timing of external admixtures, especially with the Indigenous groups from the Andes and the Pacific coast. On a continental scale, Ashaninka ancestors probably derived from a south-north migration of Indigenous groups moving into the Amazonian rainforest from a southeastern area with contributions from the Southern Cone and the Atlantic coast. These ancestral populations diversified in the variegated geographic regions of interior South America, on the eastern side of the Andes, differentially interacting with surrounding coastal groups. In this complex scenario, we also revealed strict connections between the ancestors of present-day Ashaninka, who belong to the Arawakan language family,13 and those Indigenous groups that moved further north into the Caribbean, contributing to the early Ceramic (Saladoid) tradition in the islands.14,15.

Vismodegib for treatment of periocular basal cell carcinoma - 6-year experience from a tertiary cancer center

Abstract Background: The treatment of advanced periocular basal cell carcinomas becomes a challenge as surgery may involve highly mutilating procedures. Vismodegib is the first selective hedgehog inhibitor approved for the treatment of locally advanced tumors or metastatic disease. Objective: Analyze the results of treatment with vismodegib for advanced periocular basal cell carcinomas in a real-life setting of a reference center between 2014 and 2020. Methods: Retrospective longitudinal study. The patient's demographic profile, comorbidities, tumor characteristics, and treatment outcomes were analyzed. Results: A total of 13 patients were included. Median follow-up and treatment duration were 15.9 and 10.5 months, respectively. Objective clinical response rate was 76.9%: 30.8% had a complete response and 46.2% a partial response. The median duration of response was 13 months. Progressive disease was observed in 38.5% of cases, with a median of 19 months after the beginning of treatment. Eighty-four percent of the patients had at least one adverse event, and 61.54% needed to interrupt treatment temporarily or permanently to increase tolerability. Study limitations: Being a retrospective study in a real-life setting, the evaluation of objective clinical response was subjective to physician appreciation. Conclusion: Vismodegib is a safe and effective treatment for locally advanced basal cell carcinoma. To prevent recurrences, the drug should be used continually when tolerated. The role of neoadjuvant vismodegib before surgery is being investigated and might add an important step in searching for a definitive treatment for these cases.

The Ancestry of Eastern Paraguay: A Typical South American Profile with a Unique Pattern of Admixture.

Immigrants from diverse origins have arrived in Paraguay and produced important demographic changes in a territory initially inhabited by indigenous Guarani. Few studies have been performed to estimate the proportion of Native ancestry that is still preserved in Paraguay and the role of females and males in admixture processes. Therefore, 548 individuals from eastern Paraguay were genotyped for three marker sets: mtDNA, Y-SNPs and autosomal AIM-InDels. A genetic homogeneity was found between departments for each set of markers, supported by the demographic data collected, which showed that only 43% of the individuals have the same birthplace as their parents. The results show a sex-biased intermarriage, with higher maternal than paternal Native American ancestry. Within the native mtDNA lineages in Paraguay (87.2% of the total), most haplogroups have a broad distribution across the subcontinent, and only few are concentrated around the Paraná River basin. The frequency distribution of the European paternal lineages in Paraguay (92.2% of the total) showed a major contribution from the Iberian region. In addition to the remaining legacy of the colonial period, the joint analysis of the different types of markers included in this study revealed the impact of post-war migrations on the current genetic background of Paraguay.

Vismodegib for treatment of periocular basal cell carcinoma - 6-year experience from a tertiary cancer center.

BACKGROUND: The treatment of advanced periocular basal cell carcinomas becomes a challenge as surgery may involve highly mutilating procedures. Vismodegib is the first selective hedgehog inhibitor approved for the treatment of locally advanced tumors or metastatic disease. OBJECTIVE: Analyze the results of treatment with vismodegib for advanced periocular basal cell carcinomas in a real-life setting of a reference center between 2014 and 2020. METHODS: Retrospective longitudinal study. The patient's demographic profile, comorbidities, tumor characteristics, and treatment outcomes were analyzed. RESULTS: A total of 13 patients were included. Median follow-up and treatment duration were 15.9 and 10.5 months, respectively. Objective clinical response rate was 76.9%: 30.8% had a complete response and 46.2% a partial response. The median duration of response was 13 months. Progressive disease was observed in 38.5% of cases, with a median of 19 months after the beginning of treatment. Eighty-four percent of the patients had at least one adverse event, and 61.54% needed to interrupt treatment temporarily or permanently to increase tolerability. STUDY LIMITATIONS: Being a retrospective study in a real-life setting, the evaluation of objective clinical response was subjective to physician appreciation. CONCLUSION: Vismodegib is a safe and effective treatment for locally advanced basal cell carcinoma. To prevent recurrences, the drug should be used continually when tolerated. The role of neoadjuvant vismodegib before surgery is being investigated and might add an important step in searching for a definitive treatment for these cases.

The maternal inheritance of Alto Paraná revealed by full mitogenome sequences.

Most studies on maternal lineages of South America populations are restricted to control region (CR) markers and, for some geographical regions, the number of studied samples does not adequately represent the existing diversity. This is the case of mitochondrial DNA (mtDNA) studies on Paraguay that are limited to two Native ethnic groups. To overcome this deficiency, we analysed the mitogenomes from 105 individuals living in Alto Paraná, the second most populated department of the country. Using the Precision ID mtDNA Whole Genome Panel, the molecule was sequenced on Ion S5. The majority of the haplotypes belong to the Native American lineages A, B, C and D. Analyses of maximum parsimony using mitogenome data retrieved from publications and in The 1000 Genomes Project showed a high number of new native American subclades in Paraguay. Also, none of the haplotypes found in Alto Paraná match the remaining South American samples, which include admixed populations from Colombia, Peru and Ecuador, and natives from Colombia and Ecuador. FST genetic distance analysis showed that the native genetic background of Alto Paraná has an intermediate position between the Amazonian groups and the admixed populations from Peru and Ecuador, supporting the theory about the Amazonian origin of the Tupi-Guarani and, at the same time, showing the influence of other linguistic groups.

Admixture and genetic diversity distribution patterns of non-recombining lineages of Native American ancestry in Colombian populations.

Genetic diversity of present American populations results from very complex demographic events involving different types and degrees of admixture. Through the analysis of lineage markers such as mtDNA and Y chromosome it is possible to recover the original Native American haplotypes, which remained identical since the admixture events due to the absence of recombination. However, the decrease in the effective population sizes and the consequent genetic drift effects suffered by these populations during the European colonization resulted in the loss or under-representation of a substantial fraction of the Native American lineages. In this study, we aim to clarify how the diversity and distribution of uniparental lineages vary with the different demographic characteristics (size, degree of isolation) and the different levels of admixture of extant Native groups in Colombia. We present new data resulting from the analyses of mtDNA whole control region, Y chromosome SNP haplogroups and STR haplotypes, and autosomal ancestry informative insertion-deletion polymorphisms in Colombian individuals from different ethnic and linguistic groups. The results demonstrate that populations presenting a high proportion of non-Native American ancestry have preserved nevertheless a substantial diversity of Native American lineages, for both mtDNA and Y chromosome. We suggest that, by maintaining the effective population sizes high, admixture allowed for a decrease in the effects of genetic drift due to Native population size reduction and thus resulting in an effective preservation of the Native American non-recombining lineages.