2008 Barcelona - European Society of Human Genetics

Molecular and biochemical basis of disease
P06.221
High throughput mutation screening in patients with isolated
respiratory chain complex I deficiency
M. Taverna 1 , F. Madignier 1 , B. Rolinski 2 , R. Horvath 2 , P. Freisinger 2 , T. Meitinger
1,3 , H. Prokisch 1,3 ;
1 Helmholtz Zentrum München, Neuherberg, Munich, Germany, 2 Metabolic Disease
Centre Academic Hospital München-Schwabing, Munich, Germany, 3 Institute
of Human Genetics, Technical University of Munich, Munich, Germany.
Almost 50 causal variants in nuclear genes associated with OXPHOS
disorders are known . Despite this success, in the majority of cases the
molecular defects remain unknown . Most mitochondrial disorders are
associated with three main categories of biochemical defects: respirator
chain complex I (RCC I), complex IV (RCC IV) and combined RCC
I+RCC IV deficiencies. The number of genes potentially harbouring
pathogenic mutations is very high . This situation calls for a technological
improvement for carrying out the diagnosis of this group of disorders
.
We deployed high-throughput protocols for genetic screening using
high resolution melting point analysis (Idaho-Light-Scan) . So far 96
samples have been analyzed in parallel followed by direct sequencing
of those PCR products that display divergent melting curves . We
have screened 50 genes (250 amplicons) coding for the subunits and
assembly factors of RCC I. Causative mutations have been identified
in 16% of patients. A single variant was identified in 30% of additional
samples and in 54% of samples no mutations have been found yet .
P06.222
Association of p53 polymorphism with recurrent pregnancy loss
N. Ghasemi, R. Dehghani Firouzabadi, M. Ayazi, H. Fazli, N. Tabibnejad;
Reasearch and Clinical Centre for Infertility, Yazd, Islamic Republic of Iran.
The p53 tumour suppressor gene is a well-known factor regulating
apoptosis in a wide variety of cells and tissues . Alterations in the p53
gene are among the most common genetic changes in human cancers
. In addition, recent data provide evidence that p53 plays a critical
role in mediating pregnancy by regulating steroid hormone activation .
Several polymorphisms of the p53 tumour suppressor gene have been
associated with recurrent pregnancy loss . We evaluated the hypothesis
that polymorphisms in the p53 tumour suppressor gene in women
may be associated with occurrence of repeated miscarriages .
The prevalence of a common polymorphism of the p53 tumour suppressor
gene (Arg and Pro variants at codon 72) in 50 women with
recurrent pregnancy loss compare with 50 normal women with at least
two alive children as control group . For each patient, two p53 tumour
suppressor alleles (Arg and Pro) were identified by using PCR-RLFP
technique and genotypes were defined as Arg/Arg, Pro/Pro, or Arg/
Pro . Statistical analysis was done by SPSS software and the p-values
under 0.05 were considered to be statistically significant.
The homozygous Pro/Pro genotypes were found more often (27 .5%)
among women with recurrent abortion versus other group (21 .9%) .
It is concluded that P53 codon 72 polymorphism may serve as a susceptibility
factor affecting the chances of recurrent pregnancy loss .
P06.223
DNA polymorphisms in proinflamatory citokines IL1B and IL6
are not associated to pain in spanish patients
P. Álvarez Fernaud 1,2 , C. Muriel 2,3 , J. del Pino 4 , J. Santos 1,3 , P. Armero 1,2 , R.
González-Sarmiento 1,2 ;
1 Unidad de Medicina Molecular-Departamento de Medicina, Salamanca, Spain,
2 Cátedra extraordinaria del dolor-Fundación Grünenthal. Universidad de Salamanca,
Salamanca, Spain, 3 Unidad del dolor. Servicio de anestesia. Hospital
Universitario de Salamanca, Salamanca, Spain, 4 Servicio de Reumatología.
Hospital Universitario de Salamanca, Salamanca, Spain.
The characterization of genes responsible for multifactorial diseases
with genetic substrate such as pain, can be done through linkage analysis
or association studies . Association studies can be performed with
candidate genes .
In the case of pain, in addition to genes encoding proteins involved in
neurotransmission, genes coding for inflammatory proteins can also
play an important role . We have analysed allelic variants of genes
encoding IL1B and IL6 proinflamatory proteins in order to determine
whether variants of these genes may be associated with increased
susceptibility to pain . We have studied 404 cases: 250 with neuropathic
pain and 154 with inflammatory pain, in all of them the diagnosis
was accompanied by a study of levels of pain using EVA .
Our results show no relationship betweewn allelic variants of studied
genes, neuropathic pain, inflammatory pain, or with the levels of pain
according to EVA . Therefore we conclude that pain is nnot associated
with variants IL1B and IL6 genes
P06.224
Alpha-synuclein gene duplication analysis in familial italian
Parkinson patients
F. Sironi 1,2 , P. Primignani 3 , M. Zini 1 , L. Trotta 1,4 , T. Brambilla 1 , S. Tunesi 1,5 , A.
Antonini 1 , D. A. Coviello 3 , G. Pezzoli 1 , S. Goldwurm 1 ;
1 Parkinson Institute, Istituti Clinici di Pefezionamento, Milano, Italy, 2 Medical
Genetics Laboratory, Foundation IRCCS “Ospedale Maggiore Policlinico, Mangiagalli
e Regina Elena”Genetics Laboratory, Milan, Italy, 3 Medical Genetics
Laboratory, Foundation IRCCS “Ospedale Maggiore Policlinico, Mangiagalli e
Regina Elena”Genetics Laboratory, Milano, Italy, 4 Medical Genetics Laboratory,
Foundation IRCCS “Ospedale Maggiore Policlinico, Mangiagalli e Regina
Elena”Genetics Laboratory,, Milan, Italy, 5 Institute of Medical Statistics and
Biometry, University of Milan, Milan, Italy.
Alfa-synuclein gene (SNCA) duplication or triplication was found in autosomal
dominant Parkinson disease (PD) . Our aim was to analyse
SNCA multiplication in an Italian series of familial PD .
We examined SNCA multiplication in an Italian series of 134 unrelated
Italian PD patients with at least one first degree relative affected. Our
sample population derived from the “Human genetic bank of patients
affected by Parkinson disease and parkinsonisms” (http://parkinson .
it/dnabank .htlm) . We investigated the presence of SNCA multiplication
using the MLPA approach (Kit “SALSA P51“) . The kit also allow the detection
of exon rearrangements in the PKRN, PINK1, DJ1 genes and
of two point mutations: p .G2019S (LRRK2 gene) and p .A30P (SNCA
gene). Each result was confirmed in two independent experiments.
Up to now we performed MLPA assay on the first 58 familial PD patients
.
This preliminary screening has identified 1SNCA duplication positive
patient, 1 heterozygous deleted allele in the PINK1 gene (exon 6), 1 in
the PARK2 gene (exon 3-4) and 3 mutated alleles in the LRRK2 gene
(p .G2019S in exon 41) .
The patient carrier of the SNCA duplication is a woman of 45 years of
age affected by a classical PD . She developed depression and bradikinesia
as first symptoms at 41 years. She responded to L-Dopa therapy
and does not have cognitive decline . The mother developed PD at 45
years of age and died at 60 with dementia .
Our data indicate that SNCA duplication is present also in Italian population:
approximately 1 .5% (1/58) of familial PD patient .
P06.225
Parkin mutation analysis in patients with sporadic early-onset
Parkinson’s Disease
G. Provenzano 1 , F. Annesi 1 , M. T. Pellecchia 2 , F. E. Rocca 1 , E. De Marco 1 , D.
Civitelli 1 , P. Tarantino 1 , P. Barone 2 , L. Morgante 3 , M. Zappia 4 , G. Annesi 1 ;
1 Institute of Neurological Sciences,National Research Council, Mangone (CS),
Italy, 2 Department of Neurological Sciences, University Federico II, Napoli, Italy,
3 Department of Neuroscience, Psychiatry and Anesthesiology, University of
Messina, Messina, Italy, 4 Clinica Neurologica I, Department of Neuroscience,
University of Catania, Catania, Italy.
Mutations in the parkin gene (PARK2) are responsible for about 50%
of familial autosomal recessive early onset (≤ 45 years) Parkinson’s
Disease (EOPD) and 10 to 20 % of sporadic EOPD . Recently, a novel
parkin mutation, consisting of a deletion of the promoter and exon 1 of
parkin, was described in a family with autosomal recessive EOPD and
in an isolated case with EOPD . The aim of this study is to perform mutational
analysis of the coding regions of the parkin gene in sporadic
EOPD and subsequently to investigate whether rearrangements within
both the shared promoter region and the parkin gene are present in the
patients with only one or no mutations . A total of 53 index cases with
sporadic EOPD and an age at onset ≤ 45 years from Southern Italy
were screened for parkin mutation . DNA was exstracted from peripheral
blood using standard protocols and each exon of parkin was amplified
and sequenced. Absolute quantification was perfomed by real time
PCR 7900 HT-SDS . Among 53 patients screened for parkin mutations,
8 carried single heterozygous mutations, 4 had simple homozygous
mutations, 1 was a compound heterozygous and 40 had no mutations .
Gene dosage experiment failed to reveal an exonic rearrangement of