<P<.05° ° SS oO oe ¢ & °=(%) adAyouab 99 yo Aouanbal41008060Age (years) aS ° S o °°So oO oe + N=(%) edAjoueb 99 Jo Aouanbas480 90Age (years)7060

Figure 3. Prevalence of homozygosity ( CC ) for the MTP rs2866164 SNP according to age and adjustment for buffering genotypes in Ashkenazi Jews. ( A ) Frequency of M TP CC genotype in controls and probands (range 55 – 104 y ea rs) by the specifi ed age ranges with the indicated number of subjects for each age range: 55 – 64 y ea rs = 44, 65 – 74 y ea rs = 101, 75 – 84 y ea rs = 97, 85 – 94 y ea rs = 60, and 95 – 104 y ea rs = 179. ( B ) The frequency of homozygosity for the C C genotype of the M TP rs2866164 SNP according to age with or without buffering genes in offspring and controls (see Methods for description of C ETP [rs5882] , ApoC3 [rs2542052] , AdipoQ [rs56354395]). Filled circles (and continuous line) indicate prevalence of the CC homozygosity in those that did not harbor buffer- ing genes. Open circles (and dashed line) indicate prevalence of the CC homo- zygosity in participants that harbor buffering genes. Frequency of MTP CC genotype either with or without buffering genes are given by the specifi ed age ranges with the indicated number of subjects for each age range (buffered/ unbuffered): 55 – 64 y ea rs = 32/51, 65 – 74 y ea rs = 50/72, 75 – 84 y ea rs = 42/58, 85 – 92 y ea rs = 9/22.

Figure 2. Concentration of triglycerides (TG) and two lipoproteins, VLDL and chylomicrons, which are under the physiologic control of MTP, according to MTP rs2866164 genotype ( CC vs CG/GG ) in offspring and controls. Results are adjusted for age and gender. (A ) Total plasma TG, (B ) p lasma VLDL , and ( C ) chylomicrons. Values are means ± SE . * p < .05.

case – control analyses, with only a small range around the two selected ages. Thus, these populations are unable to perform trend analysis, which is only possible in our popu- lation, due to the distribution of participants across this entire segment of the life span, where age-related mortality rate is greatest (ie, 55 – 100+ y ea rs). Indeed, as we have already mentioned, some deleterious genotype frequencies show a propensity to form a U-shape pattern with aging, and this can be a major concern in regards to distinguishing longevity and deleterious genotypes.

have led to the conclusion that genotype frequency changed very little with aging ( Figure 3A ). In contrast, comparing 70 y ea r s old to centenarians could have led us to conclude that the CC genotype is a longevity gene due to its relative enrichment in Ashkenazi probands. On the contrary, as is evident from the pattern in genotype frequency during aging ( Figure 3A ), CC genotype prevalence begins to decrease at ages where the mortality rate is expected to increase. How- ever, as individuals approach exceptional old age, there is a marked enrichment in the C C genotype, not because this genotype suddenly becomes benefi cial but rather due to the

For example, comparing only case – control analysis between 60 - y ea r - old individuals and centenarians in our study, which are on opposite ends of the “ U shape ” , would

A 1.0 0.8 0.6 P < .05 0.4 CC 0.2 CG/GG 0.0 65 70 75 80 85 90 95 100 105 Age (years) B 1.0 0.8 0.6 P = .53 0.4 CC 0.2 CG/GG 0.0 65 70 75 80 85 90 95 100 105 Age (years) )%( lavivruS)%( lavivruS

that gene variants involved in lipoprotein metabolism an important role in healthy aging and longevity.

I n summary, we show that enrichment of the MTP CC genotype in centenarians and their offspring, relative to controls, is misleading unless the pattern in genotype frequency during aging is observed. Indeed, as opposed to prior observations, which had confl icting conclusions regarding the role of this genotype in human longevity, we show that the CC genotype demonstrates all the hallmarks of a buffered-deleterious genotype. We also demonstrate that a functional consequence of the C C genotype in controls without longevity genes includes poorer survivorship. Finally, this study is a vital proof of concept for the importance of populating the “ age axis ” as well as accounting for buffering mechanisms when attempting to discern longevity genotypes from deleterious genotypes.

Downloaded from http://biomedgerontology.oxfordjournals.org/ at Ondokuz Mayis University on November 9, 2014

F unding

This work has been supported by grants from the Paul Beeson Physi- cian Faculty Scholar in Aging Award, the Ellison Medical Foundation Senior Scholar Award, the General Clinical Research Center ( M01- RR12248 ), and the Diabetes Research and Training Center ( DK20541 ) at the Albert Einstein College of Medicine and grants AG027734 , AG028872 , RR12248 , and M01RR12248 from the National Institutes of Health . D.M.H. is supported by an National Institute of Aging -sponsored K99 award (AG037574).

Acknowledgments

Figure 4. Survival Analysis according to M TP genotype in Ashkenazi offspring and controls. To describe the relationship between genotype and death, we plotted the Kaplan – Meier survival function estimates of controls by MTP genotype based upon whether or not individuals harbored a buffering gene (see Methods for description of CETP [rs5882], A poC3 [rs2542052], and AdipoQ [rs56354395]). ( A ) Kaplan – Meier curve of offspring and control Ashkenazi ’ s without buffering genes; C C genotype ( n = 43) was associated with worse survivorship than CG/GG genotypes ( n = 126) in offspring and controls without buffering genes (Wilcoxon, p < .05), ( B ) Kaplan – Meier curve of offspring and control Ashkenazi ’ s with buffering genes ( CC genotype, n = 32; CG/GG genotype, n = 71). There was no signifi cant difference in survivorship between genotypes in individuals with buffering genes (Wilcoxon, p = .53).