2008 Barcelona - European Society of Human Genetics

Normal variation, population genetics, genetic epidemiology
P07.133
the frequency of XRcc1 DNA repair gene A399G polymorphism
in the Western Anatolia
T. Sever, S. Pehlivan;
University of Gaziantep, Faculty of Medicine, Department of Medical Biology,
Gaziantep, Turkey.
The aim of our studies, to determine of XRCC1 gene at codon 399
region frequencies of polymorphisms in healthy Western Anatolia
population . We aimed XRCC1-399 polymorphism frequencies and
the genotype distribution, with respect to the polymorphic codon 399
of XRCC1 gene by PCR-RFLP (Msp I Restriction Endonuclease enzyme)
in 100 healthy individuals from the region of Izmir, Turkey . The
following genotype frequencies were observed in the Western Anatolia
population: A/A 44%, A/G 41% and G/G 15% . The frequency of A allele
is 64 .5% and the frequency of G allele 35 .5% . The presence of the
Adenin and Guanine allele frequencies in various populations such
as USA, England, Caucasians, Korean and Chinese populations are
similar to our results according to the published data .
P07.134
Phylogeography of the human Y chromosome haplogroup E3a
F. Cruciani1 , B. Trombetta1 , D. Sellitto2 , C. Nodale1 , R. Scozzari1 ;
1 2 Sapienza Università di Roma, Rome, Italy, Consiglio Nazionale delle Ricerche,
Rome, Italy.
The Y chromosome specific biallelic marker DYS271 defines the
most common haplogroup (E3a) currently found in sub-Saharan Africa
. A sister clade, E3b (E-M215), is rare in sub-Saharan Africa, but
very common in northern and eastern Africa . On the whole, these two
clades represent more than 70% of the Y chromosomes of the African
continent . A third clade belonging to E3 (E3c or E-M329) has been
recently reported to be present only in eastern Africa, at low frequencies
.
In this study we analyzed more than 1,600 Y chromosomes from 55
African populations, using both new and previously described biallelic
markers, in order to refine the phylogeny and the geographic distribution
of the E3a haplogroup .
The most common E-DYS271 sub-clades (E-DYS271*, E-M191, E-
U209) showed a non uniform distribution across sub-Saharan Africa .
Most of the E-DYS271 chromosomes found in northern and western
Africa belong to the paragroup E-DYS271*, which is rare in central
and southern Africa . In these latter regions, haplogroups E-M191 and
E-U209 show similar frequency distributions and coalescence ages
(13 and 11 kyr, respectively), suggesting their involvement in the same
migratory event/s .
By the use of two new phylogenetically equivalent markers (V38 and
V89), the earlier tripartite structure of E3 haplogroup was resolved in
favor of a common ancestor for haplogroups E-DYS271 (formerly E3a)
and E-M329 (formerly E3c) . The new topology of the E3 haplogroup is
suggestive of a relatively recent eastern African origin for the majority
of the chromosomes presently found in sub-Saharan Africa .
P07.135
Genetic variability of madeira archipelago inferred from Y
chromosome, mtDNA and HLA system
A. C. N. Lemos, H. Spinola, R. Gonçalves, A. Fernandes, A. Brehm;
Human Genetic Laboratory, Funchal, Portugal.
The Madeira Archipelago is composed by two inhabited islands, Madeira
and Porto Santo. The first settlers of these islands came from
north and south of Portugal and Europe (Flandres, France and Italy),
jointly with some African slaves .
Three geographic groups were defined within the Archipelago: Funchal
(FX), Southwest (SW) and Northeast (NE - including Porto Santo) . The
Y chromosome haplogroup followed the Y Chromosome Consortium
and comparison with both mtDNA and HLA-A, HLA-B and HLA-DRB1
genes was performed . Arlequin was used to compare the three geographic
groups within the archipelago and to calculate genetic diversity
of Y chromosome SNPs, mtDNA and HLA systems between and within
each group .
No significative haplotypic differences were found regarding the Y
chromosome SNPs for these three groups, opposite to mtDNA and
HLA systems encountered between Southwest and Funchal . We also
found major European influence although some African traces are
present . The highest level of genetic diversity was found in Funchal for
both mtDNA and HLAs .
The aim of this study was to determine the genetic background of the
Madeira population, to search for differences within the Archipelago
and find out the influence of the colonization in the actual genetic structure
of this population .
P07.136
Prehistoric migrations out of East Europe: phylogeography of
Y-chromosome haplogroups N2 and N3a
V. Kharkov 1 , O. Medvedeva 2 , K. Khamina 2 , V. Stepanov 1 ;
1 Institute for Medical Genetics, Siberian Branch of Russian Academy of Medical
Sciences, Tomsk, Russian Federation, 2 Tomsk State University, Tomsk, Russian
Federation.
To reveal the structure and phylogeography of N2 and N3a Y-chromosomal
haplogroups and to reconstruct their origin, the analysis of
YSTR-haplotypes was carried out using seven YSTR loci of NRY (DY-
S389I, DYS389II, DYS390, DYS391, DYS392, DYS393 and DYS394
(DYS19)) . A total of 234 samples belonging to N2 and 903 belonging
to N3a from different ethnic population samplings of Europe, Siberia,
Central Asia and Far East were analyzed . The results of the analysis
evidenced a higher genetic diversity for N2 and N3a haplogroups in
European populations as compared with Asian ones . Median networks
showed the occurrence of different haplotype clusters for Europeans
and Asians . Age of STR variation for N3a haplogroup was 14 .2 thousand
years (12 .3 only for Europe and 8 .6 for Siberia) and for N2 haplogroup
it was 12 .6 . A high frequency of N2 and N3a haplogroups in
some Siberian populations is the consequence of strong founder effect
events, the age of which reached 3-5 .5 thousand years . Pairwise values
of Fst showed that, in Siberia, neighboring populations were characterized
by a highier level of genetic differentiation than European
ones . Cluster analysis also revealed relative proximity of European
populations to each other as compared to Asian populations . These
results suggest that an isolation of the regional group of populations
occurred soon after the origin of the N2 and N3a haplogroups . Evenks
and Yakuts displayed highly specific overlapping N3a haplotype spectra,
atypical for other Siberian ethnic groups . Thus Eastern Europe is
the most probable place of N2 and N3a haplogroups origin .
P07.137
Y-chromosome lineages in Xhosa and Zulu Bantu speaking
populations
R. P. A. Gonçalves, H. Spínola, A. Brehm;
Human Genetics Laboratory, Funchal, Portugal.
Y-chromosome Single Nucleotide Polymorphisms have been analysed
in Zulu and Xhosa, two southern Africa Bantu speaking populations .
These two ethnic groups have their origin on the farmer’s Bantu expansion
from Niger-Congo border towards sub-Sahel regions on the
southern tip of the continent, during the past 3000 years .
Seven different Y-chromosome haplogroups were found in Zulu contrasting
with only two in Xhosa . E3a, a common haplogroup among
West sub-Saharans associated to Bantu migration was the most
prevalent in both populations (56 .9% in Zulu and 90% in Xhosa) . The
second most common haplogroup was E2 (29 .3% in Zulu and 10% in
Xhosa), present both in West and East African populations .
The present-day Zulu and Xhosa paternal legacy is essentially of West
sub-Saharan origin . Zulu population shows a most diverse genetic
influence comparing to Xhosa, revealing some pre-Bantu expansion
markers and East African influences. Zulu presents 8.6% Y-chromosome
haplogroups (A, B, J1) of non-Bantu influence that could indicate
gene flow from other populations, particularly Khoisan.
P07.138
Y-chromosome lineages and kinship relation in central Eastern
sardinia
P. Rizzu 1 , L. M. Pardo 1 , G. Piras 2 , K. J. van der Gaag 3 , D. Sondervan 1 , M.
Monne 2 , A. Gabbas 2 , N. Bradman 4 , P. de Knijff 3 , A. Ruiz-Linares 4 , P. Heutink 1 ;
1 Department of Clinical Genetics, Section Medical Genomics, Amsterdam, The
Netherlands, 2 Biomolecular and Cytogenetic Center, Dept. of Hematology and
Oncology, San Francesco Hospital, Nuoro, Italy, 3 Forensic Laboratory for DNA
Research, Leiden University, Leiden, The Netherlands, 4 The Galton Laboratory,
Department of Biology, University College London, London, United Kingdom.
Genetic isolates have been successfully used in the study of complex
traits, mainly because they allow a reduction in the complexity