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Leukocyte telomere length (LTL) has been observed to be hereditable and correlated with longevity. However, contrasting results have been reported in different populations on the value of LTL heritability and on how biology of telomeres influences longevity. We investigated whether the variability of genes correlated to telomere maintenance is associated with telomere length and affects longevity in a population from Southern Italy (20-106 years). For this purpose we analyzed thirty-one polymorphisms in eight telomerase-associated genes of which twelve in the genes coding for the core enzyme (TERT and TERC) and the remaining in genes coding for components of the telomerase complex (TERF1, TERF2, TERF2IP, TNKS, TNKS2 and TEP1). We did not observe (after correcting for multiple testing) statistically significant associations between SNPs and LTL, possibly suggesting a low genetic influence of the variability of these genes on LTL in the elderly. On the other hand, we found that the variability of genes encoding for TERF1 and TNKS2, not directly involved in LTL, but important for keeping the integrity of the structure, shows a significant association with longevity. This suggests that the maintenance of these chromosomal structures may be critically important for preventing, or delaying, senescence and aging. Such a correlation was not observed in a population from northern Italy that we used as an independent replication set. This discrepancy is in line with previous reports regarding both the population specificity of results on telomere biology and the differences of aging in northern and southern Italy.

The pathways that regulate energy homeostasis, the mechanisms of damage repair, and the signaling response to internal environmental changes or external signals have been shown to be critical in modulating lifespan of model organisms and humans. In order to investigate whether genetic variation of genes involved in these pathways contribute to longevity, a two-stage case-control study in two independent sets of long-lived individuals from Calabria (Italy) was performed. In stage 1, 317 SNPs in 104 genes were analyzed in 78 cases (median age 98 years) and 71 controls (median age 67 years). In stage 2, 31 candidate SNPs identified in stage 1 (π markers = 0.1) were analyzed in an independent sample composed by 288 cases (median age 92 years) and 554 controls (median age 67 years). Two SNPs, rs282070 located in intron 1 of the MAP3K7 gene, and rs2111699 located in intron 1 of the GSTZ1 gene, were significantly associated (after adjustment for multiple testing) with longevity in stage 2 (p = 1.1 × 10(-3) and p = 1.4 × 10(-3), respectively). Interestingly, both genes are implicated in the cellular response to internal and external environmental changes, playing a crucial role in the inflammation processes that accompany aging. Our data confirm that long-lived subjects are endowed with genetic variants that allow them to optimize these cellular responses and to better deal with environmental and internal stresses.

Several studies have shown that genetic factors account for 25% of the variation in human life span. On the basis of published molecular, genetic and epidemiological data, we hypothesized that genetic polymorphisms of taste receptors, which modulate food preferences but are also expressed in a number of organs and regulate food absorption processing and metabolism, could modulate the aging process. Using a tagging approach, we investigated the possible associations between longevity and the common genetic variation at the three bitter taste receptor gene clusters on chromosomes 5, 7 and 12 in a population of 941 individuals ranging in age from 20 to 106 years from the South of Italy. We found that one polymorphism, rs978739, situated 212 bp upstream of the TAS2R16 gene, shows a statistically significant association (p = 0.001) with longevity. In particular, the frequency of A/A homozygotes increases gradually from 35% in subjects aged 20 to 70 up to 55% in centenarians. These data provide suggestive evidence on the possible correlation between human longevity and taste genetics.

The pharmacokinetics and pharmacodynamics of morphine are under the control of several polymorphic genes, which can account for part of the observed interindividual variation in pain relief. We focused on two such genes: ABCB1/MDR1, a major determinant of morphine bioavailability, and OPRM1, which encodes for the mu-opioid receptor, the primary site of action for morphine. One hundred and forty-five patients of Italian origin undergoing morphine therapy were genotyped for the single-nucleotide polymorphism (SNP) C3435T of ABCB1/MDR1 and for the A80G SNP of OPRM1. Pain relief variability was significantly (P<0.0001) associated with both polymorphisms. Combining the extreme genotypes of both genes, the association between patient polymorphism and pain relief improved (P<0.00001), allowing the detection of three groups: strong responders, responders, and non-responders, with sensitivity close to 100% and specificity more than 70%. This study provides a good example of the possible clinical use of pharmacogenetics.