title: Does telomere length mediate associations between inbreeding and increased risk for bipolar I disorder and schizophrenia?
abstract: We have recently found that consanguinity is a risk factor for bipolar I disorder (BP1) and schizophrenia (SZ) in Egypt. Inbreeding has been associated with increased cellular stress and impaired physiological function in plants and animals. Previous studies have reported that telomere length (TL), an index of oxidative stress and cellular senescence is significantly reduced among patients with SZ or mood disorders compared with control individuals. Hence we evaluated TL as a possible mediator of the observed association between consanguinity and BP1/SZ risk. Patients with BP1 (n=108), or SZ (n=60) were compared with screened adult controls in separate experiments. TL was estimated using a quantitative PCR (qPCR) based assay. The inbreeding coefficient/consanguinity rate was estimated in two ways: using 64 DNA polymorphisms ('DNA-based' rate); and from family history data ('self report'). Significant correlation between TL and DNA based inbreeding was not observed overall, though suggestive trends were present among the SZ cases. No significant case-control differences in TL were found after controlling for demographic variables. In conclusion, reduced TL may not explain a significant proportion of observed associations between consanguinity and risk for BP1/SZ.
authors.affiliation: Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
authors.forename: Hader
authors.initials: H
authors.lastname: Mansour
authors.forename: Kodavali
authors.initials: K
authors.lastname: Chowdari
authors.forename: Warda
authors.initials: W
authors.lastname: Fathi
authors.forename: Mai
authors.initials: M
authors.lastname: Elassy
authors.forename: Ibtihal
authors.initials: I
authors.lastname: Ibrahim
authors.forename: Joel
authors.initials: J
authors.lastname: Wood
authors.forename: Mikhil
authors.initials: M
authors.lastname: Bamne
authors.forename: Salwa
authors.initials: S
authors.lastname: Tobar
authors.forename: Amal
authors.initials: A
authors.lastname: Yassin
authors.forename: Hala
authors.initials: H
authors.lastname: Salah
authors.forename: Hanan
authors.initials: H
authors.lastname: Elsayed
authors.forename: Ahmed
authors.initials: A
authors.lastname: Eissa
authors.forename: Hala
authors.initials: H
authors.lastname: El-Boraie
authors.forename: Nahed E
authors.initials: NE
authors.lastname: Ibrahim
authors.forename: Mohamed
authors.initials: M
authors.lastname: Elsayed
authors.forename: Wafaa
authors.initials: W
authors.lastname: El-Bahaei
authors.forename: Zeinab
authors.initials: Z
authors.lastname: Gomaa
authors.forename: Farha
authors.initials: F
authors.lastname: El-Chennawi
authors.forename: Vishwajit L
authors.initials: VL
authors.lastname: Nimgaonkar
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001714:Bipolar Disorder / Q000453:epidemiology / Q000235:genetics*; D016022:Case-Control Studies; D004534:Egypt / Q000453:epidemiology; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007178:Inbreeding; D016014:Linear Models; D008297:Male; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology / Q000235:genetics*; D016615:Telomere / Q000235:genetics*; D055815:Young Adult