Post by thought on Oct 9, 2010 9:27:39 GMT -5
Evaluating Self-declared Ancestry of U.S. Americans
With Autosomal, Y-chromosomal and Mitochondrial
DNA
HUMAN MUTATION Mutation in Brief (2010) Online
Ancestry selfidentification
is the result of both visible traits (with a biological basis) such as skin color combined with
cultural/sociological aspects (Bamshad and Guthery, 2007). In the present study rs1448484 appeared to be more
informative and rs16891982 less informative for differentiating U.S. Africans from continental Europeans than
continental Africans from continental Europeans. In contrast, rs16891982 was more informative for differentiating
U.S. Europeans from continental Africans than continental Europeans from continental Africans. Rs1448484 is
located within the OCA2 gene, which when mutated can lead to oculocutaneous albinism type II (MIM# 203200);
in addition, it has been previously associated with differences in pigmentation using pooled U.S. African / African-
Caribbean population and U.S. European individuals (Shriver, et al., 2003). However, there is no evidence thus far
that rs1448484 is directly involved in pigmentation variation, although it could be in LD with a functional OCA2
variant. In contrast, rs16891982 represents a non-synonymous amino acid change (F374L) in SLC45A2, and this
gene, if mutated, leads to oculocutaneous albinism type IV (MIM# 606574). Notably, the SLC45A2-374 F allele of
rs16891982 is almost fixed in Europeans (Soejima and Koda, 2007), and affects the amount of pigmentation
(Stokowski, et al., 2007). Individuals carrying the genotypes SLC45A2-374L/L or SLC45A2-374L/F tend to show a
darker skin color than SLC45A2-374F/F individuals (Cook, et al., 2009). Here we hypothesize that within the selfidentified
U.S. Europeans or U.S. Africans, individuals with the L/L or F/L genotypes would tend to declare
themselves as U.S. African whereas F/F individuals would as U.S. Europeans. In that case, the presence of
heterozygotes in U.S. Africans would decrease the In statistic more than expected with continental Europeans and
increase it between U.S. Europeans and continental Africans, as observed by our data. Although our data provide
genetic evidence for the role of skin color in the complex process of ancestry self-identification, it would be
extremely simplistic to reduce ancestry self- identification only to the type of analysis performed here.
With Autosomal, Y-chromosomal and Mitochondrial
DNA
HUMAN MUTATION Mutation in Brief (2010) Online
Ancestry selfidentification
is the result of both visible traits (with a biological basis) such as skin color combined with
cultural/sociological aspects (Bamshad and Guthery, 2007). In the present study rs1448484 appeared to be more
informative and rs16891982 less informative for differentiating U.S. Africans from continental Europeans than
continental Africans from continental Europeans. In contrast, rs16891982 was more informative for differentiating
U.S. Europeans from continental Africans than continental Europeans from continental Africans. Rs1448484 is
located within the OCA2 gene, which when mutated can lead to oculocutaneous albinism type II (MIM# 203200);
in addition, it has been previously associated with differences in pigmentation using pooled U.S. African / African-
Caribbean population and U.S. European individuals (Shriver, et al., 2003). However, there is no evidence thus far
that rs1448484 is directly involved in pigmentation variation, although it could be in LD with a functional OCA2
variant. In contrast, rs16891982 represents a non-synonymous amino acid change (F374L) in SLC45A2, and this
gene, if mutated, leads to oculocutaneous albinism type IV (MIM# 606574). Notably, the SLC45A2-374 F allele of
rs16891982 is almost fixed in Europeans (Soejima and Koda, 2007), and affects the amount of pigmentation
(Stokowski, et al., 2007). Individuals carrying the genotypes SLC45A2-374L/L or SLC45A2-374L/F tend to show a
darker skin color than SLC45A2-374F/F individuals (Cook, et al., 2009). Here we hypothesize that within the selfidentified
U.S. Europeans or U.S. Africans, individuals with the L/L or F/L genotypes would tend to declare
themselves as U.S. African whereas F/F individuals would as U.S. Europeans. In that case, the presence of
heterozygotes in U.S. Africans would decrease the In statistic more than expected with continental Europeans and
increase it between U.S. Europeans and continental Africans, as observed by our data. Although our data provide
genetic evidence for the role of skin color in the complex process of ancestry self-identification, it would be
extremely simplistic to reduce ancestry self- identification only to the type of analysis performed here.