Many BRCA1 and BRCA2 genes
mutations are unique to Spain
(Breast and Ovarian
Cancer-February 2, 2004)
According to published
research from Spain, "We screened index cases from 410 Spanish
breast/ovarian cancer families and 214 patients (19 of them men) with breast
cancer for germline mutations in the BRCA1 and BRCA2 genes, using SSCP, PTT,
CSGE, DGGE, and direct sequencing.
"We identified 60 mutations in BRCA1 and 53 in BRCA2. Of the 53 distinct
mutations observed, 11 are novel and 12 have been reported only in Spanish
families (41.5%). The prevalence of mutations in this set of families was
26.3%, but the percentage was higher in the families with breast and ovarian
cancer (52.1%)," wrote O. Diez and colleagues, Hospital Santa Cruz & San
Pablo, Genetics Service.
"The lowest proportion of mutations was found in the site-specific female
breast cancer families (15.4%). Of the families with male breast cancer
cases, 59.1% presented mutations in the BRCA2 gene. We found a higher
frequency of ovarian cancer associated with mutations localized in the 5'
end of the BRCA1 gene, but there was no association between the prevalence
of this type of cancer and mutations situated in the ovarian cancer cluster
region (OCCR) region of exon 11 of the BRCA2 gene," the researchers wrote.
"The mutations 187_188delAG, 330A > G, 5236G > A, 5242C > A, and 589_590del
(numbered after GenBank U14680) account for 46.6% of BRCA1 detected
mutations whereas 3036_3039del, 6857_6858del, 9254_9258del, and 9538_9539del
(numbered after GenBank U43746) account for 56.6% of the BRCA2 mutations,"
the researchers stated.
"The BRCA1 330A > G has a Galician origin (northwest Spain), and BRCA2
6857_6858del and 9254_9258del probably originated in Catalonia (northeast
Spain)," they added.
The researchers concluded: "Knowledge of the spectrum of mutations and their
geographical distribution in Spain will allow a more effective detection
strategy in countries with large Spanish populations."
Diez and colleagues published their findings in Human Mutation (Analysis of
BRCA1 and BRCA2 genes in Spanish breast/ovarian cancer patients: A high
proportion of mutations unique to Spain and evidence of founder effects. Hum
Mutat, 2003;22(4):301-312).
Additional information can be obtained by contacting O. Diez, Hospital Santa
Cruz & San Pablo, Genetics Service, Pare Claret 167, E-08025 Barcelona,
Spain.
The information in this article comes under the major subject areas of
Gynecology, Mutagenesis, Oncology and Women's Health. This article was
prepared by Health & Medicine Week editors from staff and other reports.
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