European Human Genetics Conference 2007 June 16 – 19, 2007 ...

Normal variation, population genetics, genetic epidemiology
age, gene expression variation of human chromosome 21 (HSA21)
genes in DS is likely to have a substantial impact on the penetrance
of DS phenotypes.
We studied gene expression variation in 14 lymphoblastoid (LCLs) and
17 fibroblast cell lines from DS individuals and an equal number of
age, sex and ethnic matched controls. Gene expression was assayed
using Taqman qRT-PCR on a total of 100 and 106 HSA21 and on 26
non-HSA21 genes in LCLs and fibroblasts respectively.
Around 42% and 62% of genes in LCLs and fibroblasts were significantly
overexpressed in the DS population (KW, pT, -384 A>G, and 67 G>A
SNPs in 130 Italian families.
From these families, we recruited 130 Italian children suffering from
either allergic extrinsic form of atopic dermatitis (EAD) or intrinsic nonallergic
form of atopic dermatitis (IAD). Genotyping was performed using
the PCR-RFLP method and automatic sequencing.
A significant difference was observed in the genotype frequency of
-426 C>T SNP between EAD and IAD children (p=0.01); and between
EAD and controls (p= 0.01). The frequency of this SNP was no different
between the IAD children and the control group (p=0.52 ). In the EAD
children, the frequency of -426 C>T SNP was no different between the
groups of mild, moderate and severe SCORAD Index (p=N.S.).
The -426 C>T polymorphism was significantly associated with the relapse
of the disease (pG and 67 G>A SNPs and
the two groups of extrinsic and intrinsic atopic dermatitis children in
respect to control group. In 48 trios selected from 68 EAD families, the
transmission disequilibrium test (TDT) showed a preferentially transmission
of -426 T allele from the parents to affected offspring.
In our Italian children, the -426 C>T of the eotaxin gene was associated
with extrinsic atopic dermatitis. Therefore, the eotaxin gene might
contribute to a characteristic “signature” for the two types of AD.
P1155. The load of Mendelian pathology in the Siberian
indigenous populations
L. P. Nazarenko, O. A. Salyukova, L. I. Minaycheva, S. V. Fadyushina;
State Research Institute of Medical Genetics, Tomsk, Russian Federation.
Summarized data of medical genetic study of some Siberian indigenous
populations (tuvinians, altayans and khakasians) are presented.
Uniformity of the methodical principles of investigation allows comparing
the load of hereditary diseases between the populations. The load
of diseases with autosomal dominant, autosomal recessive, and Xlinked
inheritance is, respectively, 0.58, 0.92 per 1000 people and 0.49
per 1000 men in tuvinian; 0.75, 1.22 per 1000 people and 0.11 per
1000 men in altayans; 1.09, 0.81 per 1000 people and 0.65 per 1000
men in khakasians. Rare genetics syndromes are observed in each
population. However, familiar cases of microtia with meatal atresia and
conductive deafness are accomulated predominantly in the tuvinians
and altayans. Factors that play a role in the unequal distribution of
hereditary diseases in Siberian indigenous populations are under way
of investigation.
P1156. STR markers in ethnic admixture studies
R. G. M. Ferreira 1 , M. M. Moura 2 , R. C. Pagotto 2 , L. M. A. Camargo 1 , B.
Beiguelman 1 , H. Krieger 1 ;
1 Departmento de Parasitologia, Instituto de Ciências Biomédicas, Universidade
de São Paulo, Brazil, São Paulo, Brazil, 2 Universidade Federal de Rondônia,