RESUMEN
The ΔF508 mutation is the most common cause of cystic fibrosis and its prevalence varies worldwide. For instance, up to 20-fold variations in its frequency have been recorded across different areas of Brazil. This study aimed to compare the distribution of ΔF508 among healthy individuals of admixed Portuguese descent from Espírito Santo (ES), a state in Southeastern Brazil, to that in a subpopulation of Pomeranian descent, considered to be an isolated group in which the European gene pool has been preserved, living in Santa Maria do Jetibá (also in ES). We found this mutation to be present at a frequency of 0.81% among the Pomeranian group, and 0% in the general ES population. No genetic differentiation was noted between the two populations examined (FST = 0.004), and these frequencies were found to be similar to those estimated in other states of Southeastern Brazil. Although the population of Santa Maria de Jetibá has retained Pomeranian traits, such as language, fair skin, and eye color, to date, there is no evidence of inbreeding in this group (FIS = -0.004). Screening healthy individuals for the ΔF508 mutation can facilitate genetic counseling for cystic fibrosis, as well as inform evolutionary and population studies.