BRCA2 in American families with four or more cases of breast or ovarian cancer: recurrent and novel mutations, variable expression, penetrance, and the possibility of families whose cancer is not attributable to BRCA1 or BRCA2.

In order to evaluate the role of inherited BRCA2 mutations in American families--particularly the appearance in America of European founder mutations--the BRCA2 coding sequence, 5' UTR, and 3' UTR were screened in 22 Caucasian American kindreds with four or more cases of breast or ovarian cancer. Six mutations were found that cause a premature-termination codon; four of them have been reported elsewhere, and two are novel. In the four families with previously seen mutations, the distinct lineages at high risk of cancer were of Dutch, German, Irish, and Ashkenazi Jewish ancestry; mutations in Europe reflect these ancestries.

BRCA1 and BRCA2 mutations in Ashkenazi Jewish families with breast and ovarian cancer.

The strongest risk factors currently known for inherited predisposition to breast and ovarian cancer are mutations in BRCA1 and BRCA2. Two mutations in BRCA1 and one mutation in BRCA2 have been identified that are present to a particularly high degree in the Ashkenazi Jewish population due to ancient founder effects. To clarify the role of ancient and novel BRCA1 and BRCA2 mutations in the Ashkenazi Jewish population, families with a strong history of breast and ovarian cancer were examined.

Human, canine and murine BRCA1 genes: sequence comparison among species.

Five to ten percent of breast cancer in the western world may be attributed to the inheritance of highly penetrant mutations in the breast and ovarian cancer susceptibility gene, BRCA1. The biological function of BRCA1 and factors affecting expressivity, such as gene-environment and gene-gene interactions, may be more effectively studied in appropriate animal models. We report the cloning and sequencing of the canine and murine BRCA1 genes and contrast the sequences with human BRCA1.

Molecular and genetic characterization of human cell lines resistant to L-asparaginase and albizziin.

Human cell lines resistant to L-asparaginase or albizziin were isolated by multistep selection of HT1080 fibrosarcoma and MIA PaCa-2 pancreatic carcinoma cells. Mutants were cross-resistant to both drugs, but more resistant to the drug used for selection. The drug-resistant cell lines expressed elevated levels of asparagine synthetase activity and protein, up to 17-fold over that of the parental cells.

Localization of the gene for X-linked recessive type of retinitis pigmentosa (XLRP) to Xp21 by linkage analysis.

The X-linked recessive type of retinitis pigmentosa (XLRP) causes progressive night blindness, visual field constriction, and eventual blindness in affected males by the third or fourth decade of life. The biochemical basis of the disease is unknown, and prenatal diagnosis and definitive carrier diagnosis remain elusive. Heterogeneity in XLRP has been suggested by linkage studies of families affected with XLRP and by phenotypic differences observed in female carriers.