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

Molecular and biochemical basis of disease
3 Université MONTPELLIER1, Montpellier, France.
The splicing of pre-mRNA is accomplished by the combinatorial recognition
of multiple degenerate signals, resulting in a network of RNAprotein
interactions across an exon and/or intron. In addition to canonical
sequence elements adjacent to splice junctions, more distant auxiliary
regulatory elements such as exonic splicing enhancers (ESEs)
and exonic splicing silencers (ESSs) play a crucial role in many RNAs
for correct splicing. Identifying functional ESE or ESS sites is rather
difficult due to the short and degenerate nature of these elements and
the lack of understanding of their sequence context. Besides the identification
of naturally occurring exonic mutations that cause splicing
defects in patients and provide valuable tools to identify such auxiliary
RNA cis-elements, we have developed a new strategy to identify splicing
signals in the dystrophin gene. This strategy is based on two complementary
approaches: (1) the bioinformatics prediction of putative
splicing signals using the Splice Site Finder software (http://www.umd.
be/SSF), and (2) the experimental validation of the in silico predicted
sequences. Functional assay relies on an easy-to-use and reliable
system based on fluorescent splicing reporter minigenes, allowing flow
cytometry analyses, in which the level of fluorescence depends on the
splicing of a tested exon. The characterization of functional cis-acting
splicing sequences such as branch points and ESEs will contribute to
the comprehensive knowledge of multiple signals that regulate splicing
of this huge gene. Also, the identified sequences could constitute
therapeutic targets of the exon-skipping strategy to reverse the severe
DMD phenotype into the milder BMD one.
P0716. Different profiles of SNPs association with high arterial
pressure syndromes
O. A. Perevesentsev 1 , V. A. Bortnikova 2 , R. I. Strjuk 2 , A. V. Karpukhin 1 , V. F.
Sitnikov 3 ;
1 Research Centre For Medical Genetics, Moskow, Russian Federation, 2 Moscow
state medical-stomatology university, Moskow, Russian Federation, 3 Russian
state medical university, Moskow, Russian Federation.
There are a number of syndromes connected with high arterial pressure
that have genetic predisposition. This circimstanse arise a question
concerning of molecular bases of genetic predisposition and
differentiation of the syndromes on association with different genes.
We investigated a role of AGT, ACE, ADRB2 and APOE genes in essential
arterial hypertension (EAH), gestantional hypertension (GH)
and preeclampsia. Different profiles of SNPs association with the syndromes
were revealed. The ADRB2 Arg16Arg variant was associated
with EAH (OR=3,84, P=0,005). The association of APOE PI-22M/Q
polymorphism with EAH was not significant. However an association
of APOE 22QQ with ADRB2 Arg16Arg among patients with EAH that
significantly increases a risk was found (OR=6,82, P=0,01). This may
be due to a contribition of dysbolism of plasmatic lipids in EAH onset.
Three genes (AGT, ACE, ADRB2) were significantly associated with
GH (OR=2,87-3,91; P=0,01-0,005). An addition GAH was characterisized
by genetic interaction between ACE D/D and ADRB2 Arg16Arg
with a risk increasing (OR=5,80, P=0,01). These results may be explained
by increasing of RAAS system activity during a pregnancy.
The AGT T235T variant was associated with preeclampsia (OR=3,2;
P=0,01). The data suggest a possibility distinguish predisposition to
the syndromes with high arterial pressure by different profiles of SNPs
association.
P0717. Inventory of TOR1A mutation carriers in France.
S. Tuffery-Giraud 1,2 , F. Clot 3,4 , A. Durr 3,5 , A. Brice 3,5 , G. Lesca 6,7 , I. Vuillaume 8,9 ,
A. Calender 6,7 , B. Sablonnière 8,9 , T. Besnard 1,2 , C. Saquet 10 , D. Thorel 10 , L. Ozelius
11 , L. Hjermind 12 , A. Roubertie 13 , L. Cif 14 , M. Claustres 1,10 , M. Frederic 1,2 , G.
Collod-Beroud 1,2 ;
1 INSERM U 827, Montpellier, France, 2 Université Montpellier 1, Montpellier,
France, 3 INSERM U 679, Paris, France, 4 Université Pierre and Marie Curie-
Paris 6, IFR70, UMR S679, Paris, France, 5 AP-HP, Groupe Hospitalier Pitié-
Salpêtrière, Département de Génétique Cytogénétique et Embryologie, Paris,
France, 6 Hôpital Edouard-Herriot, Service de Génétique Moléculaire et Clinique,
Lyon, France, 7 Université Claude Bernard Lyon 1, Villeurbanne, France,
8 CHRU de Lille, Institut de Biochimie et Biologie Moléculaire, Lille, France,
9 INSERM U 837, Lille, France, 10 CHU Montpellier, Hôpital Arnaud de Villeneuve,
Laboratoire de Génétique Moléculaire, Montpellier, France, 11 Department of
Genetics and Genome Sciences, Mount Sinai School of Medicine, New York,
NY, United States, 12 Department of Medical Genetics, The Panum Institute,
University of Copenhagen, Copenhagen, Denmark, 13 CHU Montpellier, Hôpital
Saint Eloi, Service de Neuropédiatrie, Montpellier, France, 14 CHU Montpellier,
Hôpital Saint Eloi, Service de Neurochirurgie, Montpellier, France.
Dystonia is a neurological movement disorder characterized by involuntary
movements or postures. The only currently identified primary
Early-Onset Torsion Dystonia (EOTD) gene is TOR1A that encodes
the torsinA chaperon protein. The majority of cases from various ethnic
groups are caused by a unique and recurrent autosomal dominantly
inherited deletion: c.907delGAG. EOTD prevalence in the general European
population is estimated between 0.3 to 0.5:100,000, that would
correspond to a calculated number of symptomatic carriers ranging
from 184 to 307 in the French population. Collaborations have been
established between the four French laboratories in charge of this diagnostic:
52 probands with EOTD of which 26 cases in a familial context
of the disease have been diagnosed with the mutation. Whenever
possible, the presence of the deletion in each parent, the number of
relatives carrying the mutation, and their phenotypic status (symptomatic
or asymptomatic) has been investigated. Overall, 108 individuals
were found to carry the mutation of which 20 were asymptomatic. This
number of TOR1A carriers, lower than expected, may be related to
non exhaustive testing of these families and/or lower prevalence of
TOR1A-linked dystonia in France.
Haplotypes with TOR1A flanking microsatelites could be constructed in
31 families. The common Ashkenazi Jewish (AJ) haplotype was found
in two families and the second AJ haplotype previously reported (Lebre
1999) has been found in two other families. Only one other recurrent
haplotype has been characterized in two other families confirming the
quasi absence of founder effect for the TOR1A mutation in France.
P0718. Novel splice mutation in the EDAR gene in a Lebanese
female with an atypical form of anhidrotic ectodermal dysplasia
C. Cluzeau 1 , H. Mégarbané 2 , E. Bal 1 , P. Guigue 1 , F. Stephan 3 , A. Munnich 1 , A.
Mégarbané 4 , A. Smahi 1 ;
1 U 781 INSERM, Département de Génétique, Hôpital Necker-Enfants Malades,
Paris, France, 2 Unité de Génétique Médicale, Laboratoire de Biologie
Moléculaire et Cytogénétique, Faculté de Médecine, Université Saint-Joseph,
Beyrouth, Lebanon, 3 Service de dermatologie, Hôtel-Dieu de France, Beyrouth,
Lebanon, 4 Unité de Génétique Médicale, Laboratoire de Biologie Moléculaire
et Cytogénétique, Faculté de Médecine, Université Saint-Joseph, Bayrouth,
Lebanon.
More than 170 different pathological clinical conditions have been defined
as ectodermal dysplasia (ED). They all share as common feature
abnormalities in hair, teeth, nails and sweat glands, but must be associated
with anomalies in other organs and systems. EDA is characterized
by the triad of signs comprising sparse hair, abnormal or missing
teeth and inability to sweat due to lack of sweat glands. Here we present
a 18-year-old woman, born to first cousin parents that belong to
the Lebanese Shiite Muslim community. Behind the triad of features
characteristics of EDA she presents an atypical association with various
clinical manifestations. Lacrimation was nearly absent and salivary
secretions reduced. The lips were thick and everted. The skin was
dry and velvet. Absence of breasts and a rudimentary extranumerary
areola and nipple on the left side were noted as well. She also had
marked palmar and plantar hyperkeratosis. Light microscopy of skin
biopsies showed orthokeratotic hyperkeratosis and absence of sweat
glands. We identified a novel homozygous mutation (IVS9+1 G>A) in
EDAR gene. RT-PCR performed on patient skin biopsy RNA, showed
that the mutation results in total absence of EDAR transcript and consequently
of the EDAR protein, which likely results in total abolition of
Ectodysplasin mediated NF-kB signaling. NF-kB signaling is involved
principally in early development of ectodermal appendages and in
tooth development. It’s recent involvement in embryonic salivary gland
development as well as EDAR expression in lacrimal, and mammary
glands may explain the complex phenotype observed in our patient
carrying EDAR mutation.
P0719. Functional consequences of EDAR mutations on NF-kB
and Lef-1/β-catenin signalling
C. Cluzeau 1 , E. Bal 1 , N. Chassaing 2 , S. Hadj-Rabia 3,1 , C. Bodemer 3,1 , P. Calvas
2 , M. C. Vincent 2 , A. Munnich 1 , A. Smahi 1 ;
1 U 781 INSERM, Département de Génétique, Hôpital Necker-Enfants Malades,
Paris, France, 2 Service de Génétique médicale, Hôpital Purpan, Toulouse,
France, 3 Service de Dermatologie, Hôpital Necker-Enfants Malades, Paris,
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