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

Cancer genetics
Their frequencies were also compared with patient‘s age, gender,
smoking, alcohol status, family history, and tumor histopathology in a
Turkish population.
Methods: We conducted a case-population base study including 136
cases of brain tumors and 86 population base age- and sex-matched
healthy controls to examine the role of polymorphisms of XPD gene, in
the context of brain tumor risk for the Turkish population. Tumors were
subdivided into 4 main groups that constitute 85% of brain tumors,
according to tumor histopathological examination. Group I; patients
with glial tumors (n=72), Group II; patients with meningiomas (n=35),
Group III; patients with pituitary adenomas (n=20) and Group IV; patients
with metastases to the brain (n=9).
Results: There were no significant difference among groups as compared
with each other (groups I-IV) and also compared with control
healthy individuals in regards to XPD gene polymorphisms.
Conclusion: Lys751Gln polymorphisms of the XPD gene have not a
functional consequence in brain cancer risk and do not have prognostic
significance in patients with brain tumors either.
Key Words: brain tumors, DNA repair gene, genetics, polymorphism,
xeroderma pigmentosum group D, XPD
P0505. BRCA1 and BRCA2 sequence variability in normal
population in Croatia
V. Musani 1 , M. Levacic Cvok 1 , M. Cretnik 1 , P. Ozretic 1 , A. Godan 2 , M. Markovic 3 ,
S. Levanat 1 ;
1 Division of Molecular Medicine, Rudjer Boskovic Institute, Zagreb, Croatia,
2 School of Medicine, University of Zagreb, General Practice Kalinovica, Zagreb,
Croatia, 3 Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia, Zagreb,
Croatia.
Hereditary breast cancer is characterized by an inherited susceptibility
to breast cancer. The main candidates are BRCA1 and BRCA2 genes,
which are acting as tumor suppressors, and are only genes known to
be mutated in familial history of breast cancer. In familial cases an individual
already carries a mutation in one of the alleles. Tumorigenesis
is a result of inactivation of the second allele.
We are analyzing distribution of polymorphic variants of BRCA1 and
BRCA2 genes in normal population to establish the reference values
in healthy population, since no such screening has been undertaken in
Croatia. We assume that by evaluating polymorphic forms of BRCA1
and BRCA2 predisposition to breast and ovarian cancer can be estimated.
Among a wide range of conventional mutation scanning methods
based on conformational polymorphisms, we decided to use procedures
based on high resolution melting approach and heteroduplex
formation that give different melting profile and fluorescence, according
to polymorphic or mutational variant.
This analysis is contributing to a program of an early detection and prevention
of breast cancer in Croatia with intention of forming a database
of a high penetrance susceptibility genes BRCA1 and BRCA2.
P0506. Haplotype Analysis of Recurrent BRCA1 and BRCA2
Mutations In Spain.
M. Infante, M. Duran, L. Perez-Cabornero, D. J. Sanz, E. Sanchez-Tapia, A.
Osorio, G. Llort, O. Diez, M. de la Hoya, E. Esteban-Cardeñosa, A. Vega, E.
Lastra, C. Miner, E. Velasco;
IBGM, Valladolid, Spain.
Mutational analysis of BRCA1 and BRCA2 genes has been hampered
by the large size of the two genes, and the frequent occurrence of
unique mutations. Founder mutations for BRCA1 and BRCA2 have
been identified in several populations, and haplotype analysis has provided
evidence of a common ancestor. Several mutations (c.5272-1G>A
from BRCA1, and c.3036delACAA, c.5344delAATA, c.5374delTATG
and c.9538delAA from BRCA2) have been identified multiple times in
our population, suggesting that could be founder in Spain.
Haplotype analysis using polymorphic markers spanning BRCA1 and
BRCA2 loci was performed on index cases and on additional family
members. Sixty-two BRCA1/2 positive families were genotyped.
D17S855, D17S1185, D17S1323 and D17S1326 polymorphic microsatellites
linked to the BRCA1 gene were analysed in seven c5272-1
G>A families. D13S171, D13S260, D13S1695 and D13S1698 STRs
were typed in four different BRCA2 mutations c3036delACAA (36
families), c5374delTATG (11 families), c5344delAATA (4 families), and
c9538delAA (4 families).
All carriers of c.5272-1 G>A and c.5374delTATG mutations shared
the same haplotype at the four markers of BRCA1 and BRCA2, respectively,
and thus supporting the possibility of a common ancestry.
Results in c.3036delACAA families provide evidence of at least two
distinct lines of transmission in Spanish population. This facilitates the
setting up of a less expensive and less time-consuming strategy to test
the BRCA genes in high-risk Spanish BC patients.
P0507. The complete deletion of BRCA1 gene identified in the
Slovak family by combination of sequencing, MLPA and array-
CGH techniques.
M. Konecny 1 , K. Zavodna 2 , V. Vranova 3 , M. Vizvaryova 1 , Z. Bartosova 2 , P.
Kuglik 3 , E. Weismanova 1 , I. Mlkva 4 , J. Kausitz 1 ;
1 St. Elizabeth Cancer Institute, Bratislava, Slovakia, 2 Cancer Research Institute
of Slovak Academy of Sciences, Bratislava, Slovakia, 3 Faculty of Science, Masaryk
University, Brno, Czech Republic, 4 Faculty Hospital, Bratislava, Slovakia.
Pathogenic germline substitutions and short deletions/insertions in
BRCA1/2 account for the majority of hereditary breast/ovarian cancer
cases, however, the large genomic rearrangements (LGR) also represent
a substantial proportion of disease-causing changes. In this pilot
study we demonstrate the specific case of Slovak family with breast/
ovarian cancer, where sequencing analysis (SA) of BRCA1 revealed
the discrepancy of SNPs haplotypes and primarily indicated the presence
of LGR.
Initially, the analysis of all exons of BRCA1 was based on the combination
of SSCP and SA. Subsequently, MLPA analysis (P002B; P087
kits) was performed. Finally, results were proved with array-comparative
genomic hybridization (array-CGH).
SSCP and SA demonstrated presence of 11 SNPs in BRCA1, which
indicated hemizygous status, and possible occurrence of LGR. The
MLPA results showed reduction of peaks levels for each BRCA1 exon.
Array-CGH displayed a single deletion signal for BRCA1 among set of
287 gene probes. Totally, 8 members of the family were analysed, in 3
of them LGR was confirmed.
We have discovered rare germline LGR affecting complete BRCA1,
according to our knowledge this is the second time it was described.
Although, the breakpoints of LGR were not identified yet, concerning
family history it is evident, that clinical effect is comparable with small
deletions/insertions and substitutions and leads to the loss-off gene
function.
In conclusion, it is important to note that DNA analysis of BRCA1/2
genes should be performed in all affected members of breast/ovarian
cancer families concurrently, since the discrepancy in the SNPs haplotypes
may indicate the presence of LGR.
P0508. Mutation screening of BRCA1 and BRCA2 in breast and
breast/ovarian cancer families from the Slovakia.
M. Vizvaryova1 , M. Konecny1 , E. Weismanova1 , D. Ilencikova2 , I. Mlkva3 , J.
Kausitz1 ;
1 2 St. Elizabeth Cancer Institute, Bratislava, Slovakia, National Oncological Institute,
Bratislava, Slovakia, 3Faculty Hospital, Bratislava, Slovakia.
Germline mutations in the BRCA1 and BRCA2 genes have been shown
to account for the majority of hereditary breast and ovarian cancers.
We have screened high-risk breast and breast/ovarian cancer families
from Slovakia using combination of the SSCP and direct sequencing
techniques.
Mutational analysis of all exons and flanking intronic splice sites of
BRCA1 gene was performed in 156 suspected families and subsequently
in 47 BRCA1 negative families, the analysis of complete coding
region of BRCA2 was performed.
Fourteen different types of BRCA1 pathologic mutations were identified
in 31 breast/ovarian families. The most frequently found mutations
were c.5266dupC (8 families), c.181T>G (5 families), c.68_69delAG
(3 families) and c.843_846del4 (3 families), marked in the approved
systematic nomenclature numbering. The novel BRCA1 mutation
c.1166delG, which forms a stop codon in amino acid 393 giving rise
to a truncation protein, was identified. This frame-shift mutation was
identified in 2 patients suffered from breast cancer at the ages of 27
and 32 years, and in 2 subclinical probands.
Mutational analysis of BRCA2 gene showed presence of 3 distinct
pathogenic mutations. The mutations c.3G>A, c.5946delT, c.9403delC
were found in 3 families with strong family history for occurrence of
breast cancer, all of them are already presented in BIC database.
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