2008 Barcelona - European Society of Human Genetics

Molecular and biochemical basis of disease
PS2 mutations are responsible for both early and late onset familial
AD . Promoter and intronic polymorphisms have been detected on both
PS genes and some of those have been reported as risk factors for
sporadic AD development .
With the aid to detect PS2 mutations in four unrelated late-onset AD
patients with familial history we sequenced PS2 exons 3 - 12 . Primers
were designed to amplify each exon and its surrounding sequences .
Since intron 9 is relatively small exons 9 and 10 were coamplified. No
mutation within the coding region was detected, instead all four patients
carried the haplotype TGTCG corresponding to polymorphisms
C129T on exon 3, A(-24)G on intron 3, C261T on exon 4, G(+160)C
polymorphism on intron 9 and A(+24)G on intron 11 . The polymorphism
G(+160)C, located on the shortest of all PS2 introns, had not
been identified before. The additional genotyping of fifty non-demented
age-matched control individuals revealed that the TGTCG haplotype is
present at a very low frequency (2%) in the normal population .
To conclude, the haplotype constituted by five different polymorphisms
on the PS2 gene described in the present study seems to be associated
with familial AD . The analysis of further familial late-onset AD
cases will reveal its importance as diagnostic marker .
P05.005
mutation detection in ENAm and mmP20 genes in amelogenesis
imperfecta
M. Bahaminpour, P. Aref, M. Shahrabi, M. Ghandehari Motlagh, B. Seraj, M.
Heidari;
School of Dentistry,, Tehran, Islamic Republic of Iran.
Amelogenesis imperfecta (AI) is one of the common of inherited tooth
disorders . AI is distinguished by abnormality in enamel formation . The
frequency of this disease is different through the worldwide . Studies
have demonstrated that several genes were associated with AI such
as ENAM and MMP20 genes . MMP20 gene is part of a cluster of matrix
metalloproteinase (MMP) genes . Protein of the (MMP) family is involved
in the breakdown of extracellular matrix in normal physiological
processes . ENAM is another gene and it plays crucial role in normal
teeth development . The aim of this investigation was to study mutation
detection in 10 Iranian families with non-syndromic AI . . We carried
out a polymerase chain reaction (PCR) and single-stranded conformation
polymorphism (SSCP) for mutation detection within ENAM and
MMP20 genes . SSCP analysis of genomic DNA from the AI family revealed
the presence of an abnormal conformer in the AI patients . DNA
Sequencing revealed the presence of mutation in the different part of
the subjected . We found genetic changes in patients with different type
of inheritances, one patient in exon 4 of MMP20 gene and one patient
for ENAM exon 9 . The data presented here is in agreement with the
previous studies that suggested these genes are associated with tooth
disorder. Taken together these findings support MMP20 and ENAM as
disease genes, and opened a new window on the molecular mechanism
of the AI disease and to the function of the enamelin protein in
enamel formation .
P05.006
the role of Atm in monitoring the integrity of mitotic spindle
L. Chessa 1 , A. Prodosmo 2 , A. De Amicis 1 , M. Gabriele 3 , M. Piane 1 , S. Soddu 2 ,
E. Cundari 3 ;
1 II Faculty of Medicine, Sapienza University, Roma, Italy, 2 Department of Experimental
Pathology, Regina Elena Cancer Institute, Roma, Italy, 3 Institute of
Biology and Molecular Pathology, National Research Council, Roma, Italy.
Centrosomes are cytoplasmic organelles that organize the interphase
cytoskeleton and contribute to bipolar spindle formation during mitotic
cell division . Dysfunction of the centrosome/centriole regulatory
controls can generate supernumerary centrosomes, abnormal mitotic
spindles and finally chromosomal instability.
We previously showed that during the cell cycle progression ATM is
activated by phosphorylation at Ser1981 at each mitosis and localizes
at centrosomes together with p53 phosphorylated at Ser15, so as to
keep it inactive at centrosomes when the spindle is correctly in place .
In case of disruption of mitotic spindle, as the result of nocodazole
damage, the colocalization of ATM and p53 is lost at centrosomes but
present in form of spots dispersed in the cytoplasm (Oricchio et al .,
2006) .
Here we show that in ATM-defective cells (both lymphoblasts and peripheral
blood lymphocytes from AT patients) p53 does not colocalize
at centrosomes with gamma-tubulin . In contrast, the colocalization of
p53 and gamma-tubulin takes place in Mre11-defective cells established
from an AT-LD patient . In conclusion, the monitoring of the mitotic
spindle appears to be an ATM-dependent phenomenon .
Oricchio E ., Saladino C ., Iacovelli S ., Soddu S ., Cundari E . Cell Cycle
5/1, 88-92, 2006
P05.007
incidence of NLGN genes in greek autistic patients
K. Volaki 1 , A. Pampanos 1 , O. Papadaki-Papandreou 2 , S. Giouroukos 2 , L.
Thomaidou 2 , V. Oikonomakis 1 , E. Kanavakis 1 , S. Kitsiou-Tzeli 1 ;
1 Department of Medical Genetics, Medical School of Athens University, Aghia
Sophia Children’s Hospital, Athens, Greece, 2 First Department of Pediatrics,
Medical School of Athens University, Aghia Sophia Children’s Hospital, Athens,
Greece.
Autism and Autism Spectrum Disorders (A .S .D .) belong to the group of
neurodevelopmental disorders with a prevalence of 5-10/10,000 and
male to female ratio 3-4:1 .
This study aimed to analyse the Neuroligin 3 gene (NLGN3, Xq13) and
Neuroligin 4 gene (NLGN4, Xp22 .3) in patients with A .S .D . The sample
includes 367 individuals of Greek origin (169 patients, 154 mothers,
44 first-degree relatives). All patients had been diagnosed with A.S.D.
by neurologists, psychiatrists and clinical geneticists according to the
DSM-IV criteria . Patients carrying chromosomal aberrations or Fragile
X syndrome were excluded from the study . The mutation p .Y74Y of
NLGN3 was examined with ARMS PCR whereas mutations p .R451C
of NLGN3 and p .1186insT of NLGN4 were screened by dHPLC .Mutations
p.Y74Y and p.R451C were not identified in our samples. However,
the dHPLC screening for the p .1186insT mutation suggested the
existence of a mutation in two samples (in a patient and his mother) .
Sequencing revealed the c .1597A>G mutation (p .K378R) in NLGN4 .
This gene is thought to play an important role in synaptogenesis and
synapse remodelling in the neuronal circuitry of the brain, representing
a good functional candidate for A.S.D. This is the first molecular study
of individuals with A .S .D . in Greece . Sequencing of the rest of the exons
of our samples may allow for a genotype-phenotype correlation in
the Greek population .
P05.008
Auto-brewery syndrome - genetic testing
S. Wisniewski, K. Kordel, R. Wachowiak;
University of Medical Sciences, Poznan, Poland.
The concentration of ethanol in blood, expired air and urine constitutes
important proof to accuse drunk drivers . However the reliability of alcohol
concentration analysis results is very often questioned by the
lawyers . One of the argument is the opinion that alcohol could be produced
in the body, due to “auto-brewery” syndrome - increased level
of blood alcohol caused by yeast or bacterial fermentation in the small
intestine . Moreover, endogenous alcohol is produced in blood even
after human death. Our aim was to prepare genetic test to confirm or
exclude presence of microbial flora of intestine and blood. DNA was
isolated from blood and intestinal content samples collected during
autopsies of car accidents victims and was used in PCR reaction with
universal primers targeting the conserved regions ITS1 and ITS2 . Autopsy
samples were compared with known fungal strains . The results
induced us to propose one hybridization fluorescent probe combined
with Cy5 and LNA nucleotides . The probe works with LightCycler system
in one reaction with SYBR Green and allows to detect specifically
6 common yeast species . The method seems to be fast, cost-effective
and decisive in cases of judicial doubts .
P05.009
Role of PHD fingers and COOH-terminal 30 amino acids in AIRE
transactivation activity
M. C. Rosatelli 1 , A. Meloni 2 , F. Incani 1 , D. Corda 1 , A. Cao 2 ;
1 Dipartimento di Scienze Biomediche e Biotecnologie, Cagliari, Italy, 2 Istituto
di Neurogenetica e Neurofarmacologia, Consiglio Nazionale delle Ricerche
(CNR), Cagliari, Italy.
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy
(APECED) is a rare autosomic autoimmune disease resulting from the
defective function of a gene codifying for a transcription factor named
autoimmune regulation (AIRE) . The AIRE protein contains several domains
among which two PHD fingers involved in the transcriptional