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

Molecular and biochemical basis of disease
chromosomal microdeletions in Latvia and to detect microdeletions in
AZFa, AZFb, and AZFc gene families.
Objects for Y-chromosomal microdeletions and male infertility association
study were 55 individuals with different spermatogenic arrest such
as azoospermia, severe oligozoospermia, oligo-astheno-terato-zoospermia.
All cases of spermatogenic failure resulting from endocrine
or obstructive causes or with a cytogenetic abnormality were excluded
from our study.
Microdeletions in AZF region were determined by two multiplex PCR
amplifications using ten primer pairs. Two non-polymorphic STS loci
were analyzed in each AZF region (sY84, sY86, sY127, sY134, s134,
sY254, sY255). Internal PCR control (ZFX/ZFY) was used as well as
DNA sample from a fertile male and from a female.
Out of 55 analyzed samples we have found three cases (5.5%) with
microdeletions that were observed only in AZFc region at SY254 and
SY255 STS loci in DAZ gene.
The frequency of Y-chromosomal microdeletions is low in Latvian population,
however, Y chromosome microdeletion screening is important
not only to define the aetiology of spermatogenic failure but also because
it gives precious information for more appropriate clinical management
of both the infertile male and his future male child.
P0788. Analysis of three Glycine substitutions in loop-regions
of calcium-binding Epidermal Growth Factor-like domains of
fibrillin-1: possible key positions for domain folding.
P. Khau van Kien, D. Baud, N. Pallares-Ruiz, M. Claustres;
CHU Montpellier/INSERM U827, Montpellier, France.
Among the patients refered to our centre for molecular diagnosis of
Marfan syndrome (MFS) we identified several novel heterozygous
missense mutations of the FBN1 gene. Interestingly, three of them
were predicted to result in Glycine substitutions that occur in a loopregion
of the corresponding calcium-binding Epidermal Growth Factor-like
(cb-EGF-like) domains of fibrillin-1 : c.1753G>C (p.Gly585Arg
in cb-EGF-like#5), c.4981G>A (p.Gly1661Arg in cb-EGF-like#24) and
c.6418G>A (p.Gly2140Arg in cb-EGF-like#32). These mutations were
identified in three probands with MFS (Ghent criteria fullfilled) or suspected
MFS (a criterium is missing). Familial investigations, molecular
studies (DNA/RNA), in silico analyses (conservation, 3D modeling)
coupled with data of the literature provide positive arguments for a
crucial role of the corresponding Glycine position in cb-EGF-like type 1
domain structure maintenance.
P0789. SIL1 and SARA2 mutations in a family with Marinesco-
Sjogren and Chylomicron Retention Diseases
G. Annesi 1 , P. Tarantino 1 , F. Annesi 1 , E. V. De Marco 1 , D. Civitelli 1 , A. Torroni 2 ,
A. Quattrone 1,3 ;
1 National Research Council, Mangone (Cosenza), Italy, 2 Dipartimento di Genetica
e Microbiologia, Università di Pavia, Pavia, Italy, 3 Institute of Neurology,
University Magna Graecia, Catanzaro, Italy.
Marinesco-Sjogren Syndrome (MSS) is an autosomal recessive disorder,
characterised by cataracts, ataxia, and mental retardation.Recently,
Anthonen identified the linkage of the MSS phenotype to 5q31
chromosome in a Finnish family, and identified a mutation of the SIL1
gene in all investigated MSS patients. Senderek using homozygosity
mapping in three small consanguineous families with typical MSS
narrowed a critical region on 5q31. In the current study, we further
investigated a small Italian pedigree. In this family, two brothers had
MSS syndrome, with a very low serum concentration of vitamin E
and absence of postprandial chylomicrons, a finding consistent with
chylomicron retention disease (CMRD). On a subsequent study , we
demonstrated that these two brothers carried a mutation in the SARA2
gene belonging to the Sar1-ADP-ribosylation. On the basis of the recent
data on SIL1 in MSS, we analyzed the SIL1 gene in our patients
with MSS and CMRD, in their healthy parents. Sequencing of the SIL1
gene revealed a homozygous mutation at position 331 in exon 4 resulting
in a premature stop codon at amino acid 111 (R111X) in the affected
brothers, while both parents were heterozygous for the mutation
. In our previous study , we hypothesized that both MSS and CRMD
found in the two Calabrian brothers could be due to defects in a gene
crucial to the assembly of the chylomicron particle.The present results,
however, demonstrate that CMRD and MSS observed in our patients
are distinct diseases due to defects in two different genes, SARA2
and SIL1.
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P0790. Sequence analysis of multidrug resistance protein
3 (MDR3) in Italian patients with intrahepatic cholestasis of
pregnancy with raised serum γ-GT
D. Tavian 1 , D. Degiorgio 2 , C. Redaelli 1 , N. Roncaglia 3 , P. Vergani 3 , D. A. Coviello
2 , R. Colombo 1 ;
1 Laboratory of Human Molecular Biology and Genetics, Catholic University of
the Sacred Heart, Milan, Italy, 2 Laboratory of Medical Genetics Fondazione
IRCCS, Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan,
Italy, 3 Department of Obstetrics and Gynecology, University of Milano-Bicocca,
Monza, Italy.
Intrahepatic cholestasis of pregnancy (ICP) is characterized by intense
pruritus and abnormalities of liver function tests and bile acids. Usually,
serum gamma-glutamyl transpeptidase (γ-GT) activity remains within
normal limits. However, in some cases γ-GT is increased. Although
the prognosis is generally favourable for the mother, ICP is associated
with increased fetal risks, such as preterm delivery and fetal distress.
Intrauterine fetal death has been reported in 0.8-1.6% of ICP cases.
The cause of ICP is still unknown, but there are evidences that genetically
disfunction MDR3 is associated to the development of ICP. MDR3
P-glycoprotein is a canalicular phopholipid translocator involved in the
biliary secretion of phospholipids. The aim of this study was to identify
new disease-causing mutations in a specific group of Italian women
suffering from ICP with raised serum γ-GT (>40 mg/dL). DNA sequence
analysis of the MDR3 promoter and the 27 coding exons with their
exon-intron boundaries was performed in 11 ICP patients with raised
γ-GT levels and in 43 control women. Two heterozygous mutations
were found in the ICP patients. One is a novel mutation consisting of
A to G transition at the 3’ acceptor splice site of MDR3 intron 7 (IVS7[-
2]A→G); the second one is R590Q, a mutation previously reported in a
patient with primary sclerosing cholangitis. The identification of MDR3
mutations in 18% of the affected women supports the hypothesis that
genomic variants of this gene play a pathogenetic role in the subset of
ICP patients presenting with raised γ-GT values.
P0791. The first laboratory expierence of diagnostics of MEN2
syndrome in KMUH (Lithuania)
L. Kucinskas1 , L. Juodele1 , D. Serapinas2 , A. Vitkauskiene3 , J. Jeroch4 ;
1 2 Kaunas Medical University Hospital, Kaunas, Lithuania, Kaunas Medical
University Hospital Genetic Consultation, Kaunas, Lithuania, 3Kaunas Medical
University Hospital Laboratory of Immnulogy and genetics, Kaunas, Lithuania,
4Institute for Biomedical research, Kaunas Medicine University, Kaunas, Lithuania.
MEN2 syndrome is a rare autosomal dominant syndrome with medullary
thyroid carcinoma and other tumours of endocrinological system.
MEN2 syndrome has three subtypes: MEN2A (medullary thyroid carcinoma,
pheochromocitoma and primary hyperparathyroidism), MEN2B
(medulary thyroid carcinoma, pheochromocitoma and typical phenotype
- marphanoid constitution with ganglioneuromatosis) and FMTC
(familiar medullary thyroid carcinoma). RET is the only gene known
to be associated with MEN 2. In 2006 year the diagnostics of MEN2
syndrome was performed for members of two families in Kaunas
Medical University Hospital. The molecular genetics diagnostics was
performed using two restrictions enzymes Fok I and Pag I. The first
family was of medullary carcinoma patient and her 4 year old son. The
mutation was pC618R in RET gene codon 618. The presymptomatic
diagnostics was performed for the child of patient and results showed,
that he has no mutation. Another family has the girl with medullary
carcinoma. The girl was 8 years old when operation was performed.
She had phenotypic signs of MEN2B syndrome: ganglioneuromatosis
of tongue and lips. The mutation analysis using restriction enzymes
confirmed the most typical mutation of MEN2B syndrome :p.M918T in
exon 16 of RET gene.
The molecular diagnostics using restriction enzymes is cheap, fast and
easy performed. This laboratory diagnosis can be used for confirmatory
of diagnosis, presymptomatic diagnosis and corelation between
mutation and disease prognosis.
P0792. Serine-arginine repressor protein, SRrp35, is disrupted
by an inv(6)(p21.3q15) in a patient with mental retardation and
obesity
J. G. Dauwerse 1 , K. B. M. Hansson 1 , D. J. Halley 2 , M. Kriek 1 , M. H. Breuning 1 ,
D. J. M. Peters 1 ;
1 Leiden University Medical Center, Leiden, The Netherlands, 2 Clinical Genetics