title: Leukocyte Telomere Length in Newborns: Implications for the Role of Telomeres in Human Disease.
abstract: In adults, leukocyte telomere length (LTL) is variable, familial, and longer in women and in offspring conceived by older fathers. Although short LTL is associated with atherosclerotic cardiovascular disease, long LTL is associated with major cancers. The prevailing notion is that LTL is a "telomeric clock," whose movement (expressed in LTL attrition) reflects the pace of aging. Accordingly, individuals with short LTL are considered to be biologically older than their peers. Recent studies suggest that LTL is largely determined before adulthood. We examined whether factors that largely characterize LTL in adults also influence LTL in newborns.
  
  
  
  LTL was measured in blood samples from 490 newborns and their parents.
  
  
  
  LTL (mean ± SD) was longer (9.50 ± 0.70 kb) in newborns than in their mothers (7.92 ± 0.67 kb) and fathers (7.70 ± 0.71 kb) (both P < .0001); there was no difference in the variance of LTL among the 3 groups. Newborn LTL correlated more strongly with age-adjusted LTL in mothers (r = 0.47; P < .01) than in fathers (r = 0.36; P < .01) (P for interaction = .02). Newborn LTL was longer by 0.144 kb in girls than in boys (P = .02), and LTL was longer by 0.175 kb in mothers than in fathers (P < .0001). For each 1-year increase in father's age, newborn LTL increased by 0.016 kb (95% confidence interval: 0.04 to 0.28) (P = .0086).
  
  
  
  The large LTL variation across newborns challenges the telomeric clock model. Having inherently short or long LTL may be largely determined at birth, anteceding by decades disease manifestation in adults.
authors.affiliation: Departments of Epidemiology, and.
authors.forename: Pam
authors.initials: P
authors.lastname: Factor-Litvak
authors.affiliation: Departments of Epidemiology, and New York State Psychiatric Institute, New York, New York;
authors.forename: Ezra
authors.initials: E
authors.lastname: Susser
authors.affiliation: Departments of Epidemiology, and.
authors.forename: Katrina
authors.initials: K
authors.lastname: Kezios
authors.affiliation: Biostatistics, Mailman School of Public Health, Columbia University, New York, New York;
authors.forename: Ian
authors.initials: I
authors.lastname: McKeague
authors.affiliation: Hebrew University, Hadassah School of Public Health and Community Medicine, Jerusalem, Israel;
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Kark
authors.affiliation: Department of Obstetrics and Gynecology, Christiana Care Health System, Newark, Delaware;
authors.forename: Matthew
authors.initials: M
authors.lastname: Hoffman
authors.affiliation: The Center of Human Development and Aging, New Jersey Medical School, Rutgers University, Newark, New Jersey; and.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kimura
authors.affiliation: Department of Obstetrics and Gynecology, College of Physicians and Surgeons, Columbia University, New York, New York.
authors.forename: Ronald
authors.initials: R
authors.lastname: Wapner
authors.affiliation: The Center of Human Development and Aging, New Jersey Medical School, Rutgers University, Newark, New Jersey; and avivab@njms.rutgers.edu.
authors.forename: Abraham
authors.initials: A
authors.lastname: Aviv
mesh_terms: D000328:Adult; D001683:Biological Clocks; D005220:Fathers; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007962:Leukocytes; D008297:Male; D009035:Mothers; D012737:Sex Factors; D016615:Telomere / Q000648:ultrastructure*