Genetic predisposition to elevated serum thyrotropin is associated with exceptional longevity.
BACKGROUND
Exceptional longevity is associated with raised serum TSH.


OBJECTIVE
The aim of this study was to examine whether offspring of people with exceptional longevity have elevated serum TSH and whether specific single nucleotide polymorphisms (SNPs) in the TSH-B gene and TSH receptor (TSHR) gene are associated with this phenotype.


METHODS
We measured serum TSH and free T(4) in Ashkenazi Jewish centenarians (n = 232; median age, 97 yr), their offspring (n = 366; median age, 69 yr), and age-matched controls without familial longevity (n = 163; median age, 70 yr). We determined TSH heritability, its distribution, and association with SNPs in the TSH-B and TSHR genes.


RESULTS
Offspring had higher median serum TSH [1.68 mIU/liter (97.5% confidence interval, 0.65 to 4.79 mIU/liter)], compared to controls [1.50 mIU/liter (97.5% confidence interval, 0.63 to 3.93 mIU/liter); P = 0.02], with estimated heritability of 0.33 (P = 0.004). Allele frequency of two SNPs in the promoter/enhancer region of TSHR gene, associated with increased serum TSH, was higher in centenarians and their offspring compared to controls (rs10149689 G allele frequency, 0.57 and 0.53 vs. 0.48; P = 0.001 and P = 0.08; odds ratio, 1.56 and 1.22, respectively; and rs12050077 A allele frequency, 0.57 and 0.53 vs. 0.46; P = 0.0001 and P = 0.01; odds ratio, 1.68 and 1.32, respectively). Linkage disequilibrium between the two SNPs was high (r(2) = 0.95), suggesting interaction between them. Furthermore, GA haplotype frequency was significantly higher among centenarians and offspring compared to controls (0.57 and 0.53 vs. 0.46; P = 0.0001 and P = 0.01, respectively).


CONCLUSIONS
A heritable phenotype characterized by raised serum TSH is associated with human longevity. Carriers of rs12050077 and rs10149689 SNPs in the TSHR have higher serum TSH, possibly contributing to decreased thyroid function and longevity.
Atzmon
Gil
G
Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Barzilai
Nir
N
Surks
Martin I
MI
Gabriely
Ilan
I
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D005260:Female; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D007585:Jews; D008136:Longevity / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D012044:Regression Analysis; D050436:Regulatory Elements, Transcriptional / Q000235:genetics; D013972:Thyrotropin / Q000097:blood* / Q000235:genetics*
D013972:Thyrotropin