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

Genetic analysis, linkage, and association
- and the automated denaturing high performance liquid (dHPLC)
screening method.
The MLPA method was validated by the detection of 18 known large
NF1 gene deletions. The dHPLC was optimised for a rapid screening
of the 60 exons and the splice junctions of the NF1 gene. The dHPLC
conditions were validated by the detection of 260 known variants located
in two third of the NF1 exons.
The sensitivity was evaluated in a MLPA/dHPLC analysis of a panel of
100 unrelated french NF1 patients with at least two consensus diagnostic
criterias.
Four large deletions were detected by MLPA and mutations were identified
in 91 patients with a global mutation detection rate of 96%. The
mutations included 18 deletions, 10 insertions, 33 non sens mutations,
11 missense mutations, 16 splice mutations and 3 complex rearrangements.
Our results confirm that the association of the MLPA and dHPLC techniques
provides an accurate and fast method for the identification of
NF1 mutations.
P1052. NOD2/CARD15 mutation analysis and genotypephenotype
correlation in Russian patients with Crohn‘s disease
E. V. Stepanova1 , O. A. Schagina2 , I. D. Loranskaya1 , A. V. Polyakov2 ;
1 2 RMAPE, Moscow, Russian Federation, Research centre for medical genetics,
Moscow, Russian Federation.
Crohn’s disease (CD) is a chronic inflammatory disorder of the gastrointestinal
tract with variations in localization and behavior. Mutations in
the NOD2/CARD15 gene on chromosome 16q have been implicated
in the pathogenesis of the disease and three main sequence variants,
all single nucleotide polymorphisms (SNPs). We collected a cohort of
78 CD patients and 54 population controls to determine the prevalence
of NOD2/CARD15 SNPs and their association with phenotypic
expression of the disease. All patients and controls were genotyped for
Arg702Trp, Gly908Arg and Leu1007fsinsC.
At least one mutation was present in 21,7% of patients compared to
10.0% in controls (p=0,02), in patients with Crohn disease, the allelic
frequency of R702W, G908R, and L1007fs was 22%, 8.3%, and 1,3%,
respectively. Compound heterozygotes and homozygotes occurred in
26,9% of patients and in none of the controls.
The correlation of genotype-fenotype showed a significant association
with early onset in patients with R702W or G908R, but not in patients
with L1007fs. There was not a significant association between this
SNPs carriership and inflammatory localization (p=0,08). Association
between carriage of this allels and colonic complication (p=0,004) such
as stenosis, penetration and perianal exhibitings were revealed in our
study.
In a Russian population SNPs of the NOD2/CARD15 gene were a
marker of susceptibility to Crohn disease and were associated with colonic
complication. Carriers of the R702W and G908R alleles showed
early onset of Crohn disease.
This work was pertly supported by Russian President‘s grant
NSh5736.2006.7
P1053. Opitz-Kaveggia (FG) and Lujan syndromes are allelic
having mutations in the MED12 gene
C. E. Schwartz 1 , P. S. Tarpey 2 , H. Risheg 1 , H. A. Lubs 1 , J. M. Opitz 3 , R. D.
Clark 4 , M. M. May 1 , S. Briault 5 , J. M. Graham 6 , J. Fryns 7 , G. Piluso 8 , J. Chelly 9 ,
A. Verloes 10 , C. Skinner 1 , R. C. Rogers 1 , J. B. Moeschler 11 , S. M. Joseph 1 , J.
Jones 1 , J. Gecz 12 , F. L. Raymond 13 , M. Stratton 2 , M. J. Friez 1 , R. E. Stevenson 1 ;
1 Greenwood Genetic Center, Greenwood, SC, United States, 2 Wellcome Trust
Sanger Institute, Hinkton, United Kingdom, 3 University of Utah Medical Center,
Salt Lake City, UT, United States, 4 Loma Linda University Children’s Hospital,
Loma Linda, CA, United States, 5 Centre Hospitalie Regional d’Orleans, Orleans,
France, 6 Cedars-Sinai Medical Center, Los Angeles, CA, United States,
7 Human Genome Laboratory, Leuven, Belgium, 8 Seconda Universite degli Studi
di Napoli, Napoli, Italy, 9 Institut Cochin, Paris, France, 10 Robert Debre University
Hospital, Serurier, France, 11 Dartmouth-Hitchcock Medical Center, Lebanon,
NH, United States, 12 Women and Children’s Hospital, Adelaide, Australia,
13 Cambridge Institute of Medical Research, Cambridge, United Kingdom.
FG syndrome is an X-linked mental retardation (XLMR) syndrome first
described by Opitz and Kaveggia in 1974. It is characterized by MR,
relative macrocephaly, hypotonia and constipation. Five different loci
have been reported for FG syndrome on the X chromosome. Analysis
of a candidate gene, MED12, in 24 XLMR families linked to Xq13,
identified a specific nucleotide substitution, c.2881C>T, in 2 FG families.
This change results in a missense mutation, p.R961W. Subsequent
analysis of an additional 119 patients with FG identified another
7 patients with the same mutation, meaning 7.4% of the FG patients
tested had this mutation. The mutation was not observed in more than
1400 normal males.
Independently, a systematic screen of 737 annotated Vega genes in
250 XLMR probands, identified another base change, c.3020A>G in
MED12 in the proband from the original Lujan family. This change segregated
in the family and was not observed in greater than 1400 normal
males. The c.3020A>G results in a missense mutation, p.N1007S.
Subsequent studies of 111 FG and 40 Lujan patients found another
family with the same mutation. The phenotype of the family, K9359,
consisted of height in 80 th - 90 th centile range, weight at the 40 th centile,
normal head circumference, tall narrow face, high nasal root and
behavior disturbances. This closely overlaps with Lujan syndrome: tall,
asthenic habitus, tall narrow face, high narrow palate, behavior abnormalities.
These findings in the original families with Opitz-Kaveggia (FG) and
Lujan syndromes, indicate these two XLMR syndromes are allelic, with
mutations in MED12.
P1054. A novel type of canine osteodysplasia resembling human
Osteogenesis imperfecta
M. K. Hytönen 1 , H. Lohi 2 , K. Sainio 3 ;
1 Institute of Biomedicine and Department of Molecular Genetics, University of
Helsinki, Helsinki, Finland, 2 Department of Molecular Genetics, The Folkhälsan
Institute of Genetics, University of Helsinki, Helsinki, Finland, 3 Institute of Biomedicine,
University of Helsinki, Helsinki, Finland.
Recently completed genetic analysis indicates that the dog genome
holds a wealth of information that will benefit human health. Most of the
canine inherited diseases are shared with humans. Complex genetic
problems can be simplified in dogs since each pure breed represents
a group of genetically similar animals that have descended from only
a few ancestors. We have characterized a novel congenital disorder
involving multiple skeletal defects among Brazilian Terriers. Affected
dogs have typical craniofacial features, growth retardation, joint hyperlaxity
and osteopenia based on radiographical examination. The
clinical symptoms are severe and dogs have failure to thrive within a
few weeks of life. The affected puppies have to be euthanized at an
early age. Histological analyses reveal abnormalities in bone formation
including the thinning of cortical bones and reduced amount of
cancellous bone. These pathological features of the canine osteodysplasia
resemble that of human osteogenesis imperfecta (OI). In humans,
most of the OI cases are caused either by dominant mutations
in COL1A1 and COL1A2 or recessive mutations in the cartilage associated
protein gene (CRTAP). We have excluded these three genes as
candidates using microsatellite-based association analyses. Pedigree
analysis indicates a recessive mode of inheritance. A whole genome
wide study with canine SNP chip arrays has been initiated to map the
causative gene for this novel type of canine osteodysplasia.
P1055. Predictive value of cytokine gene polymorphisms for the
development of osteonecrosis
S. Samara 1 , C. Chassanidis 1 , A. Dimitroulias 2 , Z. Dailiana 2 , T. Koromila 1 , K. N.
Malizos 2 , P. Kollia 1 ;
1 Laboratory of Medical Genetics and Cytogenetics, School of Medicine, University
of Thessaly, Larissa, Greece, 2 Department of Orthopaedic Surgery, School
of Medicine, University of Thessaly, Larissa, Greece.
Osteonecrosis of the femoral head is a disease of unknown etiology
that usually progresses to hip joint destruction necessitating total hip
arthroplasty. Cytokines, other signaling molecules and angiogenic
factors may lead to more rapid healing and filling of defects with
biomechanically competent and viable bone. Cytokine production is
determined by polymorphisms in the relevant genes. In this context,
we explored the hypothesis that these polymorphisms of the cytokine
genes may be potential genetic susceptibility factors for the progression
of osteonecrosis. The IL-1α(-899), IL-1β(-511), IL-4Ra(+1902),
TGF-β (cd10), ΤΝF-α(-308/-238), IL-4(-1098/-590) and IL-10(-1082/-
592) gene single nucleotide polymorphisms were studied in 30 healthy
donors and 50 patients with osteonecrosis. Genotyping of the polymorphisms
was detected by PCR followed by restriction fragment
length analysis. A significant association in the genotype distribution
2