2008 Barcelona - European Society of Human Genetics

Normal variation, population genetics, genetic epidemiology
Experimental and Diagnostic Medicine, Division of Medical Genetics, University
of Ferrara, Ferrara, Italy, 5 Epidemiology, University of Southern Denmark,
Odense, Denmark, 6 Wessex Clinical Genetics Service, Princess Anne Hospital,
Southampton, United Kingdom.
Fraser syndrome (FS) is rare autosomal recessive condition with classical
features of cryptophthalmos, syndactyly, and genitourinary malformations
. Abnormalities of the skull, ears, nose, and larynx are often
present as well . Due to the rarity of FS, population-based epidemiological
studies are lacking . We present the results of analysis of 24
cases of FS identified among 10 318 446 pregnancies registered in
the EUROCAT network of congenital malformation registries in 1980-
2004 period . This corresponds to a prevalence of 0 .23/100000 or 1 in
429 .935 births . Prenatal ultrasound examination detected abnormalities
in 13/24 (54 .2%) fetuses . Mean gestational age at discovery of an
abnormality by prenatal ultrasound was 22 .3±3 .2 (18-27) gestational
weeks . There were 2/24 (8 .3%) fetal deaths, 9/24 (37 .5%) pregnancy
terminations and 13/24 (54 .2%) were live born . One third of live births
did not survive the first week of life. Male:female ratio was 3.4 (17/5).
The mean birth weight in live births was 2363 ±622 g for males and
2133±413 g for females . The mean gestational age at birth was 37
weeks for both sexes . The most frequent associated congenital malformations
were urogenital (81 .8%; 18/22), eye (72 .7%; 16/22), and
limb (59 .1%; 13/22) anomalies . The mean maternal age at birth was
28 ± 5 years and the mean paternal age 31±4 years . Parental consanguinity
was present in 7/14 cases, and four families head already
one affected child (4/13) . All cases were registered in the Western part
of Europe, 12/24 (50%) cases being from Great Britain and Portugal
(prevalence 0 .49/100000 or 1 in 202859 births) .
P07.053
Analysis of frequencies of 35delG mutation in connexine 26
gene in different ethnic groups of Russia
E. I. Sharonova, S. P. Zinchenko, R. A. Zinchenko;
Research Centre for Medical Genetics, Russian Academy of Medical Sciences,
Moscow, Russian Federation.
Mutations in the GJB2 gene are a major cause of autosomal recessive
and sporadic non-syndromic hearing loss in many populations . This
study aims to determine the frequencies of 35delG mutation in different
ethnic groups of Russia .
The patients with non-syndromic hereditary hearing loss from four ethnic
groups (Chuvashs, Udmurths, Bashkirs and Russians from Rostov
Regions) were analyzed for 35delG mutation in connexine 26 gene .
Analysis of 60 patients with non-syndromic hereditary hearing loss
from Chuvash Republic, 85 patients from Rostov Region, 36 patients
from Republic of Bashkortostan, 58 patients from Udmurt Republic,
showed that frequency for 35delG mutation was specific to Russian
ethnic group (42 .86%, 45%, 8 .33%, 62 .5%, respectively) . Among the
patients with non-syndromic hereditary hearing loss from other ethnic
groups, frequencies of 35delG mutation were 5% for Chuvashs, 2 .44%
for Udmurths, 6 .06% for Bashkirs .
More then 2574 healthy donors from five ethnic groups from Russia
(Chuvashs, Maries, Udmurths, Bashkirs and Russians from Tver and
Rostov Regions) were analyzed for 35delG mutation in GJB2 gene .
Significant differencies in mutation frequencies between different ethnic
groups were discovered . Analysis showed that frequency of 35delG
mutation for Chuvashs ethnic group was 0 .48% (5 chromosomes with
mutation 35delG out of 1040 analysed (5/1040)), for Maries - 0 .99%
(8/804), for Udmurths - 0 .25% (3/1184), for Bashkirs - 0 .25% (2/792),
for Russian - 1 .44% (19/1320) .
According to this research, contribution of 35delG mutation in connexine
26 gene to the development of non-syndromic hereditary hearing
loss in various ethnic groups of Russia is different .
P07.054
N680s and -29 (G->A) FsH-R polymorphisms in czech fertile
male and female population
M. Macek sr. 1 , H. Kluckova 1 , P. Norambuena 1 , T. Piskackova 1 , M. Balascakova
1 , M. Koudova 1 , A. Stambergova 1 , M. Macek jr. 1 , J. Gromoll 2 ;
1 Department of Biology and Medical Genetics, Charles University, Second Medical
School and University Hospital Motol, Prague, Czech Republic, 2 Institute of
Reproductive Medicine, Muenster, Germany.
The aim of this study was the determination of the genotype characteristics
of FSH-R polymorphism in position -29 (G->A) and exon 10
N680S in fertile couples in families indicated for prenatal diagnosis, or
with risk of cystic fibrosis, risk of trombophilic disorders and chronic
pancreatitis dispositon in male and female Czech population .
Polymorphism -29 (G->A) was examined in 318 females and 303
males, exon 10 N680S in 317 females and 304 males . The exon 10
and promotor polymorphisms were analyzed by allelic discrimination
on ABI Prism 7000 detection system (Applied Biosystems) .
The promotor polymorphism A/A in females was 5 .03 %, in males 6 .93
%; A/G in females 37 .74 %, in males 35 .31 %; G/G in females 57 .23
%, in males 57 .76 % . Exon 10 polymorphism Asn/Asn was 37 .22 % in
females, 27 .96 % in males; Asn/Ser in 47 .32 % for females, 50 .33 %
for males; Ser/Ser in 15 .46 % in females and 21 .71 % in males . It is
apparent, that in both types of FSH-R polymorphisms no differences
were disclosed between males and females .
The genotype 680 exon 10 polymorphism Asn/Asn, Asn/Ser, Ser/Ser
are not different from so far published prevalence in Caucasian population
.
These data provide possibility to compare the genotype characteristic
of FSH-R polymorphisms for association studies in male and female
reproductive disorders and for the pharmacogenetic strategy in hormonal
treatment and stimulation in male and female patients .
Supported by grants NR9448-3/2007 and 00000064203 .
P07.055
Epidemiologic study of isolated gastroschisis in mexican
population: 1978-2006
J. Arteaga, L. Luna, O. M. Mutchinick;
National Institute of Medical Sciences and Nutrition “Salvador Zubirán”, Mexico
city, Mexico.
Isolated gastroschisis (IGC) cluster in the offspring of very young mothers
. Incidence reported range between 0 .40 and 4 .49 per 10000 births .
Recently has been observed an increase in the frequency without a
clear explanation, although several studies have identified consistent
risk factors (RF) . The increasing prevalence in newborns observed in
a sample of the Mexican populations prompted us to analyze the secular
trend for IGC and the following RF: maternal age, primigravidity,
socioeconomic status, use of vasoactive medications and change of
paternity . The information was obtained from the RYVEMCE; a hospital
based multicentric case-control study . We studied IGQ in a sample
of 1’066,542 newborns analyzing time trends prevalence from January
1978 to December 2006 and the mentioned RF in both, mothers of IGC
cases and controls. P