BRCA1 and BRCA2 germline mutations in Sardinian breast cancer families and their implications for genetic counseling.
BACKGROUND
The Sardinian population is genetically homogeneous and could be useful in understanding better the genetics of a complex disease like breast cancer (BC).


METHODS
Using a screening assay based on a combination of single-strand conformation polymorphism, denaturing high-performance liquid chromatography and sequence analysis, 47 Sardinian families with three or more BC cases were screened for germline mutations in BRCA1 and BRCA2 genes.


RESULTS
Three BRCA1/2 germline sequence variants were identified. While BRCA2-Ile3412Val is a missense variant with unknown functional significance, BRCA2-8765delAG and BRCA1-Lys505ter are two deleterious mutations (due to their predicted effects on protein truncation), which were found in seven families (15%). BRCA2-8765delAG was found in six of eight (75%) BRCA1/2-positive families and seven of 501 (1.4%) unselected and consecutively collected BC patients. Prevalence of BRCA1/2 mutations in BC families was significantly correlated with the total number of female BCs (P <0.01) and increased by the presence of (i) at least one case of ovarian or male BC, or (ii) three generations affected, or (iii) bilateral BC.


CONCLUSIONS
Identification of such features should address BC patients and their families to genetic counseling and BRCA1/2 mutational analysis. In addition, this is the first report of a detailed BRCA1/2 mutation screening in Sardinia, having immediate implications for the clinical management of BC families.
Palmieri
G
G
Institute of Molecular Genetics, Consiglio Nazionale Ricerche, Alghero, Italy. gpalmieri@yahoo.com
Palomba
G
G
Cossu
A
A
Pisano
M
M
Dedola
M F
MF
Sarobba
M G
MG
Farris
A
A
Olmeo
N
N
Contu
A
A
Pasca
A
A
Satta
M P
MP
Persico
I
I
Carboni
A A
AA
Cossu-Rocca
P
P
Contini
M
M
Mangion
J
J
Stratton
M R
MR
Tanda
F
F
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000235:genetics*; D018567:Breast Neoplasms, Male / Q000453:epidemiology / Q000235:genetics; D004252:DNA Mutational Analysis; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D005817:Genetic Counseling / Q000592:standards* / Q000639:trends; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D018095:Germ-Line Mutation; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D016133:Polymerase Chain Reaction / Q000379:methods; D018807:Polymorphism, Single-Stranded Conformational; D011159:Population Surveillance; D012307:Risk Factors; D016019:Survival Analysis
D014408:Biomarkers, Tumor