title: Male/female ratio in centenarians: a possible role played by population genetic structure.
abstract: All the demographic surveys on the centenarians have highlighted that females outnumber males. The centenarians' male/female (M/F) ratio reported by most studies ranges between 1:4 and 1:7. A puzzling 1:2 ratio was observed in Calabria, a Southern Italian region. To our knowledge only in Sardinia a similar phenomenon had been previously observed. We have therefore used the data of the Italian Institute of Statistics to figure out the centenarians' M/F ratio in the Italian regions. We found that this ratio gradually decreases from South to North. Such a result is certainly due to many factors. Thus, we have explored the possibility, it is also influenced by the genetic structure of the Italian population. In fact, the distribution of the centenarians' M/F ratio turned out to be significantly correlated with the genetic structure of the Italian population as outlined by the principal component analysis.
authors.affiliation: Dipartimento di Biologia Cellulare, Università degli Studi della Calabria, 87030 Rende, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Passarino
authors.forename: C
authors.initials: C
authors.lastname: Calignano
authors.forename: A
authors.initials: A
authors.lastname: Vallone
authors.forename: C
authors.initials: C
authors.lastname: Franceschi
authors.forename: B
authors.initials: B
authors.lastname: Jeune
authors.forename: J M
authors.initials: JM
authors.lastname: Robine
authors.forename: A I
authors.initials: AI
authors.lastname: Yashin
authors.forename: L L
authors.initials: LL
authors.lastname: Cavalli Sforza
authors.forename: G
authors.initials: G
authors.lastname: De Benedictis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008136:Longevity / Q000235:genetics*; D011157:Population Dynamics; D011159:Population Surveillance; D012744:Sex Ratio