Options
Mutations of hMSH2 and hMLH1 in Breast Cancer
Date Issued
1998-07-31
Date
1998-07-31
Author(s)
張金堅
DOI
872314B002136
Abstract
Defects in the DNA mismatch repair genes, hMLH1 and hMSH2, have been detected in
colon cancers. Mutations in these two genes combined account for up to 60% in hereditary
nonpolyposis colorectal cancer (HNPCC) and 15% in sporadic colon cancers. The mutation
spectra show no hot spots. Mutations of these two genes have also been detected in ovarian
and gastric cancers. However, the roles of these two genes in breast cancers were not well
studied.
In Taiwan, breast cancer is one of the most common malignancies in women. Increasing
number of cases and early onset have been noted recently. To find the possible genetic factors
involved in the carcinogenesis, we screen 40 breast cancer patients for hMLH1 and hMSH2
mutations. Six (15%) and five (12.5%) patients have mutations in hMLH1 and hMSH2 genes,
respectively. The overall mutation rates are about the same as those of sporadic colon cancers.
There is no association between mutations and family history. However, the majority of
mutations were found in the patients younger than 50 years old (five out of six for hMLH1
and three out of five for hMSH2). The two hMSH2 mutations in the older group have the same
C to A transversion, which do not change the encoded amino acid (glycine157). Therefore,
these two mutation events should be considered as polymorphism. Although there are obvious
differences between mutation rates of the young and old groups (19.2% vs. 7.1% for hMLH1,
and 11.5% vs. 0% for hMSH2), they are not statistically significant because of low case
numbers.
In summary, frequencies of mutation in the mismatch repair genes hMLH1 and hMSH2
are high in the Taiwanese sporadic breast cancers with early onset (30.7%) and the mutations
have no hot spots. Defects in these two genes may play important roles in tumorigenesis of
breast cancers with early onset.
colon cancers. Mutations in these two genes combined account for up to 60% in hereditary
nonpolyposis colorectal cancer (HNPCC) and 15% in sporadic colon cancers. The mutation
spectra show no hot spots. Mutations of these two genes have also been detected in ovarian
and gastric cancers. However, the roles of these two genes in breast cancers were not well
studied.
In Taiwan, breast cancer is one of the most common malignancies in women. Increasing
number of cases and early onset have been noted recently. To find the possible genetic factors
involved in the carcinogenesis, we screen 40 breast cancer patients for hMLH1 and hMSH2
mutations. Six (15%) and five (12.5%) patients have mutations in hMLH1 and hMSH2 genes,
respectively. The overall mutation rates are about the same as those of sporadic colon cancers.
There is no association between mutations and family history. However, the majority of
mutations were found in the patients younger than 50 years old (five out of six for hMLH1
and three out of five for hMSH2). The two hMSH2 mutations in the older group have the same
C to A transversion, which do not change the encoded amino acid (glycine157). Therefore,
these two mutation events should be considered as polymorphism. Although there are obvious
differences between mutation rates of the young and old groups (19.2% vs. 7.1% for hMLH1,
and 11.5% vs. 0% for hMSH2), they are not statistically significant because of low case
numbers.
In summary, frequencies of mutation in the mismatch repair genes hMLH1 and hMSH2
are high in the Taiwanese sporadic breast cancers with early onset (30.7%) and the mutations
have no hot spots. Defects in these two genes may play important roles in tumorigenesis of
breast cancers with early onset.
Subjects
breast cancer
DNA mismatch repair
mutation
SDGs
Publisher
臺北市:國立臺灣大學醫學院外科
Coverage
計畫年度:87;起迄日期:1997-08-01/1998-07-31
Type
report
File(s)
Loading...
Name
872314B002136.pdf
Size
50.04 KB
Format
Adobe PDF
Checksum
(MD5):6784a038475db4dd6831d03ee8df4c30