Genetic history of Calabrian Greeks reveals ancient events and long term isolation in the Aspromonte area of Southern Italy

Abstract

Calabrian Greeks are an enigmatic population that have preserved and evolved a unique variety of language, Greco, survived in the isolated Aspromonte mountain area of Southern Italy. To understand their genetic ancestry and explore possible effects of geographic and cultural isolation, we genome-wide genotyped a large set of South Italian samples including both communities that still speak Greco nowadays and those that lost the use of this language earlier in time. Comparisons with modern and ancient populations highlighted ancient, long-lasting genetic links with Eastern Mediterranean and Caucasian/Near-Eastern groups as ancestral sources of Southern Italians. Our results suggest that the Aspromonte communities might be interpreted as genetically drifted remnants that departed from such ancient genetic background as a consequence of long-term isolation. Specific patterns of population structuring and higher levels of genetic drift were indeed observed in these populations, reflecting geographic isolation amplified by cultural differences in the groups that still conserve the Greco language. Isolation and drift also affected the current genetic differentiation at specific gene pathways, prompting for future genome-wide association studies aimed at exploring trait-related loci that have drifted up in frequency in these isolated groups.

Clinical Network for Big Data and Personalized Health: Study Protocol and Preliminary Results

“…Furthermore, the present study may serve as a substrate to investigate population genetic history of the country at a fine-grained resolution. Indeed, the genetic history of Southern Italy is characterized by a generally high degree of outbreeding, except for a few linguistic and genetic isolates [ 29 , 30 , 31 ], and notable contaminations from both Northern Africa and Eastern Europe over the centuries [ 32 ]. Moreover, to the best of our knowledge, other datasets are specific for one disease, e.g., heart failure [ 33 ] or viral infection [ 34 ], while our study involved a lot of different chronic disorders or physiological conditions (e.g., pregnancy) in a large population from Southern Italy.…”

Amyloid Precursor Protein A713T Mutation in Calabrian Patients with Alzheimer’s Disease: A Population Genomics Approach to Estimate Inheritance from a Common Ancestor

“…To contextualize the seven AD cases in the genetic variability of Southern Italy, a panel of 84 healthy individuals, already typed for the same set of genome-wide markers, were used as controls [ 22 ]. In particular, the control panel included 20 individuals from the province of Benevento as representatives of a non-Calabrian Southern Italian population, as well as 26 and 38 individuals from the Calabrian provinces of Cosenza and Catanzaro, respectively, to approximate the Calabrian area where the affected families presumably originated [ 22 ].…”

Calabria as a Genetic Isolate, a Model for the Study of Neurodegenerative Diseases

“…Calabria is a region of southern Italy of 1 839 352 inhabitants [1], which constitutes the tip of the "boot" of Italy, the Strait of Messina separates it from Sicily, and it is suspended between two seas, the Ionian Sea and the Tyrrhenian Sea [2]. This strategic geographical position has favored various migratory flows both in pre-historical and historical times (e.g., Greek, Phoenician and Carthaginian colonization, Roman, Arab and Norman conquest) that have determined the presence of different genetic layers in the current population [3,4].…”