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Sao Tome

Saturday 12 May 2007

Two main Y-chromosome haplogroups were found in the population of Sao Tome e Principe (STP) archipelago:

- haplogroup-E3a is very common among sub-Saharans and accounts for 84.2% of the paternal lineages

- haplogroup-R1b is typical of West Eurasia and represents 8.7% of the overall male population.

Nevertheless, a significant heterogeneous distribution of R1b has been detected among the two main ethnic groups of the archipelago: Forros (10.3%) and Angolares (6.6%).

Together, haplogroups known to be prevalent in West Eurasia reach 12.5% of the chromosomes analyzed unequally distributed among the two groups: Forros present 17.7% while Angolares display only 8.2% of west Eurasian haplogroups.

It has been suggested that, despite its sub-Saharan genetic background, a relevant contribution of European paternal lineages is present in nowadays STP population. This influence has shown to be stronger in Forros than in Angolares, which could be explained by the social isolation that these have last experienced through their history.


- Goncalves R, Spinola H, Brehm A. Y-chromosome lineages in Sao Tome e Principe islands: Evidence of European influence. Am J Hum Biol. 2007 May-Jun;19(3):422-8. PMID: 17420998

- Trovoada MJ, Tavares L, Gusmao L, Alves C, Abade A, Amorim A, Prata MJ. Dissecting the genetic history of Sao Tome e Principe: a new window from Y-chromosome biallelic markers. Ann Hum Genet. 2007 Jan;71(Pt 1):77-85. PMID: 17227478

- Mateu E, Comas D, Calafell F, Perez-Lezaun A, Abade A, Bertranpetit J. A tale of two islands: population history and mitochondrial DNA sequence variation of Bioko and Sao Tome, Gulf of Guinea. Ann Hum Genet. 1997 Nov;61(Pt 6):507-18. PMID: 9543551