Table 2 shows allele frequencies for C282Y morphisms analyzed by gender. We note that none of our young controls had high prevalence rates for C282Y (or S65C) gene mutations. Our observations are consistent with those recently reported in a large sample of the population from southern Italy (0.15%, 18.6% and 0.15%, for C282Y, H63D and S65C respectively), with the C282Y mutation being the lowest yet reported for a population of European origin. We also found that possession of the C282Y allele, associated with an increase of iron uptake, significantly increased the possibility of reaching longevity in women but not in men. These data suggest that gender is a major variable in the genetics of longevity, with men and women following different strategies to reach longevity.

It is intriguing that HFE mutations may be involved in unsuccessful aging too. H63D mutations might anticipate sporadic late-onset Alzheimer's disease clinical presentation in susceptible individuals. In another study, C282Y and H63D mutations were over-represented in men and under-represented in women with familial Alzheimer's disease (FAD). Thus, the possibility that HFE mutations are important new genetic risk factors for AD should be pursued further.

Regarding the biological significance of HFE heterozygous status, this phenotype was recently defined. The mean serum iron concentrations, ferritin levels and transferrin-saturation values were higher in heterozygous subjects than in normal ones, as were mean hemoglobin levels and mean corpuscular volume. The prevalence of iron deficiency anemia was lower in women who carried HFE mutations. Concerning the significance of iron in immune responses, a delicate balance exists inside the host cell. Too much iron down-regulates microbicidal effector mechanisms and favors the growth of the pathogen, whereas too little iron is inhibitory to the induction of antimicrobial processes. However, it is undeniable that iron plays a significant role in regulating immune responses.

In conclusion, our data show that women carriers of C282Y mutation have a higher frequency among the elderly compared with control women. This suggests that this polymorphism plays a role in determining lifespan, at least in the Sicilian generation under study. These findings add another piece of evidence to the complex puzzle of genetic and environmental factors involved in controlling lifespan expectancy in humans.

Materials and Methods:

We studied 141 unrelated healthy Sicilians randomly selected, including 106 young controls (age range from 22 to 55 years; 40 men and 66 women) and 35 elderly subjects (age range from 91 to 105 years; seven men and 28 women). Written informed consent for enrolling in the study and for personal data management had been previously obtained from all the subjects according to Italian laws. Blood specimens were collected in tripotassium EDTA sterile tubes, immediately stored at -70°C, and later processed for HFE genotyping. Genomic DNA extraction was carried out according to Miller et al and stored at -20°C for HFE gene analysis.

We used a multiplex PCR kit to type C282Y, H63D, and S65C HFE mutations together with V53M, V59M, H63H, Q127H, E168Q, E168X, W169X, Q283P mutations (Oberkanins et al). The kit also enabled us to evaluate the Y250X mutation at TFR2 gene sequence. We performed the test according toItaly), and a final concentration of 200 mM each deoxynucleotide and 1 reaction buffer (PE Biosystem), 1 mM of F1, R1 and F2M primers, and 0.2 mM of R2W primer. Cycling was performed at 96°C for 7 min and 35 cycles at 95°C for 30 s, 64°C for 30 s, and 72°C for 30 s, followed by a final extension of 10 min at 72°C. PCR products were detected by electrophoresis on a 2% agarose gel, obtaining a 521 bp product and a 257 and/or 136 bp bands from mutated or wild HFE Y282C sequences. H63D alleles were typed with the amplification refractory mutation system/polymerase chain reaction (ARMS/PCR) using two separated primer couples (F3/R3 and F4/R3)50 in the following conditions. Fifty ng of template DNA were mixed in a final volume of 20 l with 0.5 U TaqGold-DNA polymerase (PE BioSystem), 200 mM each deoxynucleotide and 1 reaction buffer, and 0.5 mM of each specific primer. Cycling was performed at 96°C for 10 min and 35 cycles at 95°C for 30 s, 64°C for 30 s, and 72°C for 30 s, followed by a final extension of 10 min at 72°C. PCR products were evaluated by electrophoresis on a 2% agarose gel. Detection of a 178 bp PCR product in one or both electrophoresis lanes allows identification of homozygous or heterozygous subjects for H63D genotypes. S65C specificities were evaluated after H63D genotyping using the same ARMS/PCR protocol and appropriate primer couples. 63H homozygous subjects were typed using F5/R3 and F6/R3 primer mixes, whereas 63D subjects were typed using F7/R3 and F8/R3. All four primer mixes were used to type H63D heterozygous subjects. Statistical analysis: Allele frequencies were evaluated by gene count, and 2x2 tables were constructed to determine statistical significance (Fisher exact test) of differences in allele frequency for the HFE polymorphisms between oldest old and controls. According to Bonferroni, obtained P-values were corrected by multiplying for the number of alleles under study, i.e., 6. References: To validate our results and evaluate the presence of other less common HFE mutations and the recently described hemochromatosis-related TFR2 Y250X mutation30, a commercially purchased Reverse-Hybridization assay was used (Haemochromatosis Kit, Nuclear Laser Medicine, Settala Milanese, Italy). This... 

Note: The original text had inconsistent spacing between words and some misspellings. I corrected them while preserving the original meaning of the text.following references provide information on the prevalence of hemochromatosis and HFE gene mutations in different populations: