Research Article Characterization of Ancestral Origin of Cystic Fibrosis of Patients with New Reported Mutations in CFTR César Paz-y-Miño , 1 Ana Karina Zambrano , 1 Juan Carlos Ruiz-Cabezas, 2,3,4 Isaac Armendáriz-Castillo , 1 Jennyfer M. García-Cárdenas , 1 Santiago Guerrero, 1 Andrés López-Cortés , 1 Andy Pérez-Villa , 1 Patricia Guevara-Ramírez , 1 Verónica Yumiceba , 1 and Paola E. Leone 1 1 Centro de Investigación Genética y Genómica, Facultad de Ciencias de la Salud Eugenio Espejo, Universidad UTE, Av. Mariscal Sucre and Mariana de Jesús, Block I, Quito 170129, Ecuador 2 Universidad de Especialidades Espíritu Santo (UEES), Guayaquil, Ecuador 3 Instituto de Biomedicina, Universidad Católica de Santiago de Guayaquil, Guayaquil, Ecuador 4 Instituto Oncológico Nacional de la Sociedad de Lucha Contra el Cáncer (ION-SOLCA), Guayaquil, Ecuador Correspondence should be addressed to César Paz-y-Miño; cesar.pazymino@ute.edu.ec César Paz-y-Miño and Ana Karina Zambrano contributed equally to this work. Received 8 July 2019; Accepted 6 May 2020; Published 2 June 2020 Academic Editor: Hugh D. Smyth Copyright © 2020 César Paz-y-Miño et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The incidence of cystic fibrosis (CF) and the frequency of the variants reported for CFTR depend on the population; furthermore, CF symptomatology is characterized by obstructive lung disease and pancreatic insufficiency among other symptoms, which are reliant on the individual's genotype. The Ecuadorian population is a mixture of Native Americans, Europeans, and Africans. That population admixture could be the reason for the new mutations reported in a previous study by Ruiz et al. (2019). A panel of 46 Ancestry Informative Markers was used to estimate the ancestral proportions of each available sample (12 samples in total). As a result, the Native American ancestry proportion was the most prevalent in almost all individuals, except for three patients from Guayaquil with the mutation [c.757G>A:p.Gly253Arg; c.1352G>T:p.Gly451Val] who had the highest European composition. 1. Introduction Cystic fibrosis (CF) is an autosomal recessive disorder that has been extensively studied among populations [1]. It is characterized by obstructive lung disease, pancreatic insuffi- ciency, diabetes, and liver disease, among others [2]. The most frequent worldwide mutation in Cystic Fibrosis Trans- membrane Conductance Regulator (CFTR) protein gene is c.1521_1523delCTT (p.Phe508del) [3] which originated between 11,000 and 34,000 years ago in Europeans, then it spread across all Europe [4]. CF occurs in 1 out of 2,500 live births with high prevalence in the European ancestry, and the frequency of the heterozygotes has been reported as 1 in 25 in Europeans [5] [6]. There are plenty of studies in CF, yet the majority in Europeans, underrepresenting the Latin Americans [4] [6] [7] [8]. In the United States, a study reported the CF incidence to be 1 in 9,200 Hispanics and 1 in 10,900 Native Americans, yet the USA has a different population structure to South America [1] [6] [9]. In gen- eral, in Latin America, the incidence is 1 per 6,000 live new- borns; specifically, Ecuador exhibits an incidence of 1 in 11,252 newborns [10–12]. The Ecuadorian population, located in the northwest of South America, is a mixed population conformed by Native Americans, Europeans who arrived in the 16 th century dur- ing the conquest, and Africans who came with them as slaves. According to the last census, the population projection for 2020 was estimated as 17,510,643 Ecuadorians. Moreover, Ecuadorian self-identified as “mestizos” 71.9%, “montubios” 7.4%, Afro-Ecuadorian 7.2%, “indígenas” 7%, “blancos” Hindawi BioMed Research International Volume 2020, Article ID 9074760, 6 pages https://doi.org/10.1155/2020/9074760