Heritability of telomere length across three generations of Korean families

Abstract

Background: Leukocyte telomere length (LTL), an indicator of aging, is influenced by both genetic and environmental factors; however, its heritability is unknown. We determined heritability and inheritance patterns of telomere length across three generations of families.

Methods: We analyzed 287 individuals from three generations of 41 Korean families, including newborns, parents, and grandparents. LTL (the ratio of telomere repeat copy number to single gene copy number) was measured by quantitative real-time PCR. We estimated heritability using the SOLAR software maximum-likelihood variance component methods and a pedigree dataset. With adjustment for age and length of marriage, Pearson's partial correlation was performed for spousal pairs.

Results: Heritability of LTL was high in all participants (h² = 0.64). There were no significant differences in correlation coefficients of telomere length between paternal and maternal lines. There was a positive LTL correlation in grandfather-grandmother pairs (r = 0.25, p = 0.03) but not in father-mother pairs. After adjusting for age and length of marriage, the relationship between telomere lengths in grandfathers and grandmothers disappeared. There were inverse correlations between spousal rank differences of telomere length and length of marriage.

Conclusions: LTL is highly heritable without a sex-specific inheritance pattern and may be influenced by a shared environment.

Fig. 1. Telomere length by generation and sex of the study participants.

p Values were calculated by t tests or ANOVA. T/S ratio ratio of telomere repeat copy number to single gene copy number.

Fig. 2

Correlations of telomere lengths between newborns and parents (a), between newborns and paternal grandparents (b), between newborns and maternal grandparents (c), between parents and grandparents (d), and between husbands and wives (e). Pearson’s partial correlation coefficients were calculated with age adjustment. For multiple tests, significant level was corrected using the Bonferroni method 0.008 (= 0.05/6) (a–c).