2008 Barcelona - European Society of Human Genetics

Molecular and biochemical basis of disease
4 Corporació Sanitària Parc Taulí, Sabadell, Spain, 5 Departament de Genètica,
Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain, 6 CIBER Enfermedades
Raras, Instituto de Salud Carlos III, Barcelona, Barcelona, Spain.
Objective: To map the disease-causing gene in a large Spanish kindred
with familial hemiplegic migraine (FHM), migraine with aura (MA)
and migraine without aura (MO) .
Methods: DNA samples from 20 family members were obtained . Patients
were classified according to ICHD-II criteria for specific migraine
subtypes . After ruling out linkage to known migraine genetic loci, a
single nucleotide polymorphism (SNP)-based, 0 .62 cM density genomewide
scan was performed .
Results: In 13 affected subjects, FHM was the prevailing migraine
phenotype in six, MA in four and MO in three . Linkage analysis revealed
a disease locus in a 4 .15 Mb region on 14q32, with a maximum
two-point LOD score of 3 .1 and a multipoint parametric LOD score of
3 .8 . This genomic region does not overlap with reported migraine loci
on 14q21-22 . Several candidate genes map to this region . Sequence
analysis of one of them, SLC24A4, encoding a potassium-dependent
sodium/calcium exchanger, failed to show disease-causing mutations
in our patients .
Conclusions: The finding of a new genetic locus in FHM underscores
its monogenic character and hints to greater genetic heterogeneity
than previously suspected . While several genes conferring increased
susceptibility to migraine seem to reside on 14q, the underlying disease-causing
gene in our family remains unidentified.
P06.109
Association study of tOR1A gene polymorphisms with the risk
of primary focal dystonia
E. Sarasola 1 , F. Sádaba 2 , B. Huete 2 , A. Rodríguez-Antigüedad 2 , A. M. Pérez-
Miranda 1 , M. J. García-Barcina 1 ;
1 Unidad de Genética. Hospital de Basurto. Osakidetza - Servicio Vasco de
Salud, Bilbao, Spain, 2 Servicio de Neurología. Hospital de Basurto. Osakidetza
- Servicio Vasco de Salud, Bilbao, Spain.
The most frequent cause of early-onset primary generalised dystonia,
which is dominantly inherited, is a deletion of a GAG triplet from exon
5 of TOR1A gene (c .907delGAG) . This gene encodes torsinA protein,
whose role has been suggested to be involved in regulating nuclear
envelope and endoplasmatic reticule organization . This 3-bp deletion
removes a codon in the C-terminus of torsinA that normally encodes a
glutamic acid residue, producing an altered protein, with reduced or no
activity, which forms perinuclear inclusions .
A recent study described the effects of a new polimorphism in position
c .646 (G>C) which causes the development of inclusions similar to
those described for deltaGAG deletion . Moreover, this D216H aminoacid
change reduced the number of torsinA inclusions in cultured cells
with deltaGAG deletion . Many groups have studied the implication of
this and other polymorphisms in this gene in primary dystonia but results
are controversial. In this work we will try to find a risk haplotype
for primary focal dystonia .
We analyzed 6 different polymorphisms in individuals with focal dystonia
(n = 60) and a control healthy population (n = 50) . None of them
presented the GAG deletion in TOR1A exon 5 . For genotyping, realtime
PCR followed by allelic discrimination or PCR and automated sequencing
was performed . Statistical analysis was carried out using a
haplotype-based approach .
P06.110
molecular diagnosis of Friedreich‘s ataxia in macedonian
patients
S. A. Kocheva 1,2 , S. Vlaski-Jekic 3 , M. Kuturec 2 , G. D. Efremov 1 ;
1 Macedonian Academy of Sciences and Arts, Research Center for Genetic Engineering
and Biotechnology, Skopje, The former Yugoslav Republic of Macedonia,
2 Pediatric Clinic, Medical Faculty, Skopje, The former Yugoslav Republic
of Macedonia, 3 Department of Neurology, Medical Faculty, Skopje, The former
Yugoslav Republic of Macedonia.
Friedreich’s ataxia (FRDA) is a progressive neurodegenerative disorder
of autosomal recessive inheritance, in which gait ataxia followed by
upper limb ataxia, dysarthria, nystagmus, areflexia, loss of joint position
sense, and spastic paraparesis develop from the second decade
of life . It is the commonest hereditary ataxia, with a prevalence of 1 in
50 000 and a deduced carrier frequency in European populations of 1
in 120 . Friedreich’s ataxia has been associated with mutations of the
frataxin gene on chromosome 9 (X25 at 9q13) . In this paper we present
our results from the molecular analysis of frataxin gene (X25) gene
in total of 40 patients with spinocerebellar ataxia from the Republic of
Macedonia . Fifteen of the patients have an early onset of progressive
ataxia (before 25 years), while 25 patient were more than 25 years old
at the time of diagnosis. We amplified the FRDA associated expanded
fragment using a long range PCR technique . PCR product were
analyzed by agarose and/or PAG electrophoresis . Mutation analysis
shown that 14/15 patient with typical early onset of the simptoms were
homozygous for a GAA expansion in intron 1 of frataxin gene . No expansion
of the GAA repeat were found in 25 patient with ataxia more
than 25 years old . In 35 normal individuals the number of GAA repeat
were in normal range .
P06.111
molecular characterization of two variants of GAtA4 in patients
with congenital Heart Defects
F. Giacopelli 1 , M. Marini 1 , E. Damato 2 , A. Baban 1 , G. Trocchio 3 , G. D’Annunzio 2 ,
M. Lerone 1 , G. Pongiglione 3 , R. Lorini 2 , R. Ravazzolo 1 ;
1 Molecular Genetics and Cytogenetics Unit, Genoa, Italy, 2 Pediatric Clinic, G.
Gaslini Institute, Genoa, Italy, 3 Unit of Cardiology,G. Gaslini Institute, Genoa,
Italy.
Congenital Heart Defects (CHDs) are among the most common developmental
anomalies that affect around 1% of newborns . One of the
genes described as causative of CHD is GATA4, a zinc finger trancription
factor, important regulator in heart development . Mice lacking this
gene have defects in the formation of heart tube and are lethal . GATA4
mutations have been found in families with Atrial and Ventricular Septal
Defects and rarely associated with Tetralogy of Fallot .
In this study we report two different variants in the non coding sequence
of GATA4 gene found in two patients with Atrial Septal Defect: c784-3
C>T and c998-4C>G . Interestingly, in one of the two cases neonatal
permanent diabetes was present in the patient and her mother .
These variants were not detected in more than 100 healthy controls,
while one of the two was also detected in the apparently patient’s unaffected
mother . Both patients were screened also for TBX5 and NKX2 .5
genes and no mutations were found .
These GATA4 variants are located at acceptor splicing sites in intron 3
and 5, respectively, and predicted to be potentially able to affect splicing
on the basis of specialized software analysis .
Since the gene is not expressed in lymphocytes and fibroblasts, the
effect on splicing cannot be directly tested on cDNA . Therefore an in
vitro assay to verify the effect of both nucleotide variants using an exon
trapping model has been set up .
The Health e Child IST-2004-027749 project is acknowledged .
P06.112
the distribution of s19W and -1131 t>c gene apolypoproteid
A5 (ApoA ) polymorphism in children with innate risk factors of
metabolic syndrome
A. P. Khmyrova1 , A. N. Voitovich1 , P. A. Sinicin2 , O. A. Kononova1 , M. Y. Scherbacova2
, V. I. Larionova1 ;
1 2 State Pediatric Medical Academy, Saint-Petersburg, Russian Federation, Russian
State Medical University, Moscow, Russian Federation.
The risk factors of cardiovascular disorders there are in children and
adolescence and sometimes may be cause of metabolic syndrome .
One of metabolic syndrome criteria is atherogenic dyslipidemia with
high level of triglyceride and low level of high density lipoprotein’s cholesterol
. The detecting of molecular markers of this dyslipidemia is one
of the important problems .
The aim of our study was to investigate genotype and alleles distribution
S19W and -1131 T>C ApoA5 gene polymorphism in children
with risk factors of cardiovascular disorders and compare it with control
group .
We included 187 children with risk factors of coronary artery disease
(CAD) from 5 to 17 years old . Control group consisted of 150 children
and adolescence with same age .
For detecting S19W and A-1131T>C ApoA5 gene polymorphism we
used PCR with restriction assay by the method, described Talmud P .
J . et al ., 2002 .
We have revealed significant differences in genotype distribution (SS-
90,4% and 81,9%, SW - 9,6% and 16,8%, WW - 0,0% and 1,3%,
p=0,05, relatively) and alleles distribution (S-95,2% and 90,3%, W-