Functional variant of KLOTHO: A breast cancer risk modifier among BRCA1 mutation carriers of Ashkenazi origin

I. Wolf*, Y. Laitman, T. Rubinek, L. Abramovitz, I. Novikov, R. Beeri, M. Kuro-O, H. P. Koeffler, R. Catane, L. S. Freedman, E. Levy-Lahad, B. Y. Karlan, E. Friedman, B. Kaufman

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

46 Scopus citations


Klotho is a transmembrane protein that can be shed and act as a circulating hormone and is a putative tumor suppressor in breast cancer. A functional variant of KLOTHO (KL-VS) contains two amino acid substitutions F352V and C370S and shows reduced activity. Germ-line mutations in BRCA1 and BRCA2 substantially increase lifetime risk of breast and ovarian cancers. Yet, penetrance of deleterious BRCA1 and BRCA2 mutations is incomplete even among carriers of identical mutations. We examined the association between KL-VS and cancer risk among 1115 Ashkenazi Jewish women: 236 non-carriers, 631 BRCA1 (185delAG, 5382insC) carriers and 248 BRCA2 (6174delT) carriers. Among BRCA1 carriers, heterozygosity for the KL-VS allele was associated with increased breast and ovarian cancer risk (hazard ratio 1.40, 95% confidence intervals 1.08-1.83, P0.01) and younger age at breast cancer diagnosis (median age 48 vs 43 P0.04). KLOTHO and BRCA2 are located on 13q12, and we identified linkage disequilibrium between KL-VS and BRCA2 6174delT mutation. Studies in breast cancer cells showed reduced growth inhibitory activity and reduced secretion of klotho F352V compared with wild-type klotho. These data suggest KL-VS as a breast and ovarian cancer risk modifier among BRCA1 mutation carriers. If validated in additional cohorts, the presence of KL-VS may serve as a predictor of cancer risk among BRCA1 mutation carriers.

Original languageEnglish
Pages (from-to)26-33
Number of pages8
Issue number1
StatePublished - Jan 2010


FundersFunder number
Koschitzky Family Foundation for Breast Cancer Research
Sackler Faculty of Medicine, Tel Aviv University
Breast Cancer Research Foundation
United States-Israel Binational Science Foundation2005150
United States-Israel Binational Science Foundation
Israel Cancer Association
Ministry of Health, State of Israel4055_3
Ministry of Health, State of Israel


    • BRCA
    • Breast cancer
    • Insulin growth factor-1
    • Klotho
    • Ovarian cancer
    • Tumor suppressor


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