Table 2 Across-birth-cohort variation in degree of skewness (DS) of X-inactivation in age-matched septuagenarian twin cohorts (LSADT and MADT) and singleton centenarian cohorts (1895, 1905 and 1915 birth cohorts).
Age-matched septuagenarian twins | Centenarian singletons | ||||
|---|---|---|---|---|---|
LSADT | MADT | 1895 Birth Cohort | 1905 Birth Cohort | 1915 Birth Cohort | |
Baseline | Baseline | Baseline | Baseline | Baseline | |
Birth year | 1917–1923 | 1931–1937 | 1895 | 1905 | 1915 |
Blood draw year | 1997 | 2008–2011 | 1996–1997 | 2005 | 2015 |
Number of individuals | 234 | 59 | 33 | 81 | 98 |
Mean age, years, (range) | 76 (73–79) | 75 (73–79) | 101 | 100 | 100 |
Skewed DS 80+ (%) | 35 | 25 | 61 | 43 | 45 |
Extremely skewed DS, 95 + (%) | 8 | 2 | 19 | 12 | 10 |
Mean DS (SD) | 73 (14) | 69 (13) | 81 (11) | 75 (14) | 76 (14) |
