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

Genetic analysis, linkage, and association
Those results confirm previously reported findings that large deletions
in PTCH region may also cause Gorlin syndrome through haploinsuficiency
of PTCH gene.
P1083. Mutation analysis of the PVR and PVRL2 genes in
patients with non-syndromic cleft lip/palate
M. A. Sözen 1,2 , J. C. Murray 3 , J. T. Hecht 4 , I. McIntosh 5 , M. M. Talarova 6 , R. A.
Spritz 2 ;
1 Department of Medical Biology, School of Medicine, Afyonkarahisar Kocatepe
University, Afyonkarahisar, Turkey, 2 Human Medical Genetics Program, University
of Colorado at Denver and Health Sciences Center, Aurora, CO, United
States, 3 Department of Pediatrics, University of Iowa, Iowa City, IA, United
States, 4 Department of Pediatrics, University of Texas Medical School, Houston,
TX, United States, 5 Institute of Genetic Medicine; Johns Hopkins University,
Baltimore, MD, United States, 6 Department of Orthodontics, University of
the Pacific, San Francisco, CA, United States.
Non-syndromic cleft lip with or without cleft palate (nsCL/P, MIM
119530) is one of the most common major birth defects. Genetic linkage
and association studies have implicated loci in the 19q13 in nsCL/
P. Several candidate genes in the 19q13 region have been studied
and allelic associations with nsCL/P reported. We carried out mutation
analysis of the PVR and PVRL2 genes in this chromosomal region due
to their close homology to PVRL1, a gene involved both in an autosomal
recessive CL/P syndrome, CLPED1, and in nsCL/P in patients
from northern Venezuela. We screened a total of 73 nsCL/P patients
and 105 healthy controls from North America, and 94 patients and 94
controls from Venezuela for sequence variants in PVR and PVRL2 as
candidate genes for nsCL/P. We detected a total of 10 variants in the
PVR gene and 2 variants in the PVRL2 gene; however, none of these
showed individual significant association with nsCLP in cases versus
controls. Indeed, only one non-synonymous PVR variant, A67T, was
more frequent in the nsCLP patients than in controls, though this difference
was not significant. Altogether, no variants were significantly associated
with risk of nsCL/P in both populations. Together, these data
suggest that variants of PVR and PVRL2 genes are not major genetic
risk factors for nsCL/P, at least in the North American and Venezuelan
populations studied.
P1084. Gene dosage quantification by using multiplex
polymerase chain reaction and capillary electrophoresis
C. C. Hung1 , W. L. Lin1 , Y. N. Su2,3 ;
1Institute of Biomedical Engineering, College of Medicine and College of Engineering,
National Taiwan University, Taipei, Taiwan, 2Graduate Institute of Clinical
Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan,
3Department of Medical Genetics, National Taiwan University Hospital, Taipei,
Taiwan.
Many genetic diseases are known caused by the presence of point
mutations, small insertions and deletions in respective genes; however,
the number of diseases caused by deletions and duplications
involving large DNA genomes are significantly increasing. It would
lead to under-express or over-express according to changes in gene
dosage. In contrast, the methods for the detection of point mutations,
small insertions or deletions are well established, but the detections of
larger genomic deletions or duplications are more difficult. Due to the
lack of efficient and in-house protocol for gene dosage quantification,
we hereby describe a diagnostic protocol employing a combination of
available methods. The efficient and accurate gene dosage quantification
platform is combined the multiplex PCR with capillary electrophoresis
(CE), and applied on several entities of genes, including SMN,
PMP22 and alpha-globin genes. The reliability of the novel methodology
demonstrated it is relative speed and low-cost procedure as a
significant tool in genetic diagnosis. Its sensitivity and specificity for
identify the deletions and duplications genotypes are 100%. Moreover,
once we have established this powerful system, we will further apply
this technique on rapid detection of trisomy syndromes and microdeletion
syndromes, including trisomy 13, trisomy 21, Down syndrome,
DiGeorge syndrome and others.
P1085. New approaches for the estimation of renin-angiotensinbradykinin
system genes polymorphism
A. S. Glotov 1,2 , O. O. Favorova 3 , A. V. Favorov 4 , G. I. Obraztsova 5 , T. E.
Ivaschenko 1 , T. V. Nasedkina 2 , V. S. Baranov 1 ;
1 Ott’s Institute of Obstetrics&Gynecology, St.-Petersburg, Russian Federation,
2 Engelgardt Institute of Molecular Biology, Moscow, Russian Federation, 3 Cardiology
Research Center, Moscow, Russian Federation, 4 Bioinformatics Laboratory
of GosNIIGenetika, Moscow, Russian Federation, 5 Saint-Petersburg State
Pediatric Academy, St.-Petersburg, Russian Federation.
The rennin-angiotensin-bradykinin system is regulated by the number
of genes and possesses crucial role in the development of cardiovascular
diseases. However, interpretation of multi-gene associations
usually encounters substantial problems in evaluation of particular
gene polymorphism contribution in pathogenesis of the disease. So,
there is a clear cut necessity for the development of new approaches
for more objective evaluation of gene testing studies.
Present work focuses on the different approaches based on standart
χ-test, the “score” analysis with using Mann-Whitney U test and
Bayesian statistical approaches coupled to Markov chain Monte Carlo
(MCMC) techniques. Analysis of REN (I9-83G>A), AGT (M235T), ACE
(I/D), AGTR1 (1166A>C), AGTR2 (3123C>A), BKR2 (-58T>C and I/D)
genes in children with arterial hypertension was shown that application
MCMC techniques with/or the “score” analysis can be used for studing
multi genes associations.
P1086. Association study of IRF5 gene with Rheumatoid Arthritis
in the TUNISIAN population
M. Ben Hamad1 , E. Petit2 , G. Chabchoub1 , S. Barbet3 , S. Marzouk4 , Z. Bahloul4
, H. Ayadi1 , F. Cornelis5 , A. Maalej1 ;
1 2 Laboratoire de Génétique Moléculaire Humaine, sfax, Tunisia, Laboratoire de
Recherche Européen pour la polyarthrite Rhumatoïde, Evry, France, 3Labora toire de Recherche Européen pour la polyarthrite Rhumatoïde,, Evry, France,
4 5 Service de Médecine Interne CHU Hédi Chaker, sfax, Tunisia, Laboratoire de
Recherche Européen pour la polyarthrite Rhumatoïde, evry, France.
Rheumatoid Arthritis (RA) is an autoimmune, systemic disease which
is characterized by inflammation of synovial tissues, leading to cartilage
and bone destruction. It affects ~1% of the general population.
The susceptibility to RA involves genetic and environmental factors. In
the present study we have analysed the Interferon Regulatory Factor
5 (IRF5) which is involved in the production of cytokines implicated in
RA pathophysiology, such as tumor necrosis factor alpha, interleukine
6 and type I Interferon. In order to search an association of IRF5 rs
2004640 T allele in Tunisian population, we have analysed 101 unrelated
patients affected with RA with a mean age of 54 years and
a sex ratio (F/M) of 5.6/1 and 100 healthy controls. DNAs genotyping
was carried out with a TaqMan 5’ allelic discrimination assay on
an ABI 7500 real time PCR machine (assay:C___9491614_10). Data
were analyzed by χ2-test, and Odds Ratio (OR) with 95% confidence
interval (95% IC) was calculated. Our results showed that T/T genotype
was more frequent in RA patients compared to controls (44%
vs 24.7%; p= 0.007) (OR = 0.68; IC = [0.46-1.01]). While in the RF
positive subgroup the frequency of the T allele and T/T genotype were
significantly increased compared with the controls (p=0.011; p= 0.003,
respectively) (OR = 0.57; IC = [0.36-0.88]). In conclusion, our results
support the involvement of IRF5 gene in the genetic susceptibility to
RA in the Tunisian population.
P1087. Evidence for Further Genetic Heterogeneity in Restless
Legs Syndrome
E. B. Skehan, A. Manal, C. K. Hand, N. A. Parfrey;
University College Cork, Cork, Ireland.
Introduction: Restless legs syndrome (RLS) is a common neurological
disorder characterised by a distressing need or urge to move the
legs, usually accompanied by an uncomfortable sensation in the legs
described as a crawling, muscle ache or tension. The symptoms follow
a circadian pattern with a significant increase during the evening or
night which leads to nocturnal sleep disruption and daytime somnolence.
Molecular genetic approaches have identified five loci on chromosomes
12q, 14q, 9p, 20p, and 2q, in RLS families from different
populations. No disease-causing gene has yet been identified.
Aim: The goal of this research was to localise and identify the gene
responsible for the syndrome in a newly identified Irish autosomal
dominant RLS family.
Method: Fourteen members of the new RLS3002 family participated in
the study; ten members are affected and four are unaffected. The five
current RLS loci were examined for linkage.
Results: The results indicated exclusion of linkage to the five identified
RLS loci.
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