{"id":{"repo_id":"vcu","oai_identifier":"oai:scholarscompass.vcu.edu:etd-1024"},"canonical_url":"https://search.dev.ndltd.org/etd/vcu/oai:scholarscompass.vcu.edu:etd-1024","repository":{"repo_id":"vcu","name":"Virginia Commonwealth University","base_url":"https://scholarscompass.vcu.edu/do/oai/"},"display":{"title":"Age-related genetic and epigenetic chromosomal changes: A twin study","abstract":"The primary aims of this study were to examine acquired genetic and epigenetic changes that occur in individuals with increasing age and to determine how these changes are influenced by genetic/environmental factors. Acquired genetic changes were assessed by determining the frequency and chromosomal contents of spontaneously occurring micronuclei in identical and fraternal twins. A total of 115 individuals (48 twin pairs and 19 singletons) were evaluated, ranging in age from 7 to 85 years. As expected, micronuclei frequencies, which are indicative of genomic damage, significantly increased with age (p<0.0001, r=0.446). The majority of micronuclei (32%) contained sex chromosomes and the frequency of sex chromosome-bearing micronuclei significantly increased with age (p<0.0001). The frequency of autosome-containing micronuclei was not significantly influenced by age or gender. However, some autosomes were seen more (chromosomes 4, 8, and 9) or less (chromosomes 17 and 22) frequently than expected by chance (p<0.05). An evaluation of the numerical contents of the sex chromosome-containing micronuclei and their corresponding binucleates showed that the majority of the binucleates had an abnormal chromosomal complement (either hypodiploid or hyperdiploid), with the subset of binucleates having a normal chromosomal complement decreasing with age for both the Y chromosome in males and the X chromosome in females. Model fitting, implemented in Mx, showed the variation in the frequency of micronuclei to be best explained by either additive genetic and unique environmental components, or common and unique environmental factors. Specific environmental exposures and health conditions that were shown to influence micronuclei frequencies, included: multivitamins, leafy green vegetables, fruit, vitamin E supplements, arthritis, heart disease, allergies, and alcohol. To assess acquired epigenetic changes, global methylation profiles of two identical twin pairs were compared and found to differ, indicating that individuals do develop alterations in their methylation profiles with age. Furthermore, the twin pair having a significant difference in their micronuclei frequencies and environmental exposures had more differences in their methylation pattern compared to the twin pair whose micronuclei frequencies and environmental factors did not differ. Overall, genetic and epigenetic changes were shown to occur with age and to be influenced by genetic and lifestyle factors.","abstract_html":"The primary aims of this study were to examine acquired genetic and epigenetic changes that occur in individuals with increasing age and to determine how these changes are influenced by genetic/environmental factors. Acquired genetic changes were assessed by determining the frequency and chromosomal contents of spontaneously occurring micronuclei in identical and fraternal twins. A total of 115 individuals (48 twin pairs and 19 singletons) were evaluated, ranging in age from 7 to 85 years. As expected, micronuclei frequencies, which are indicative of genomic damage, significantly increased with age (p&lt;0.0001, r=0.446). The majority of micronuclei (32%) contained sex chromosomes and the frequency of sex chromosome-bearing micronuclei significantly increased with age (p&lt;0.0001). The frequency of autosome-containing micronuclei was not significantly influenced by age or gender. However, some autosomes were seen more (chromosomes 4, 8, and 9) or less (chromosomes 17 and 22) frequently than expected by chance (p&lt;0.05). An evaluation of the numerical contents of the sex chromosome-containing micronuclei and their corresponding binucleates showed that the majority of the binucleates had an abnormal chromosomal complement (either hypodiploid or hyperdiploid), with the subset of binucleates having a normal chromosomal complement decreasing with age for both the Y chromosome in males and the X chromosome in females. Model fitting, implemented in Mx, showed the variation in the frequency of micronuclei to be best explained by either additive genetic and unique environmental components, or common and unique environmental factors. Specific environmental exposures and health conditions that were shown to influence micronuclei frequencies, included: multivitamins, leafy green vegetables, fruit, vitamin E supplements, arthritis, heart disease, allergies, and alcohol. To assess acquired epigenetic changes, global methylation profiles of two identical twin pairs were compared and found to differ, indicating that individuals do develop alterations in their methylation profiles with age. Furthermore, the twin pair having a significant difference in their micronuclei frequencies and environmental exposures had more differences in their methylation pattern compared to the twin pair whose micronuclei frequencies and environmental factors did not differ. Overall, genetic and epigenetic changes were shown to occur with age and to be influenced by genetic and lifestyle factors.","abstract_has_math":false,"creators":["Jones, Kimberly"],"institution":null,"degree_name":"Doctor of Philosophy","degree_level":"Dissertation","degree_discipline":"Pathology","degree_department":null,"school":null,"contributors":["Colleen Jackson-Cook"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2009,"date_issued":"2009-11-06T08:00:00Z","date_published":"2009-11-06T08:00:00Z","updated_at":"2026-07-24T05:53:18Z","subjects":["Medical Pathology","Medical Sciences","Medicine and Health Sciences"],"languages":[],"rights":["© The Author"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarscompass.vcu.edu/etd/25"],"render_values":[{"text":"https://scholarscompass.vcu.edu/etd/25","href":"https://scholarscompass.vcu.edu/etd/25","code":true}]}]},"links":{"outbound_url":"https://doi.org/10.25772/4GZ3-NH22","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Colleen Jackson-Cook"]},{"key":"dc:creator","label":"Author","values":["Jones, Kimberly"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2014-12-11T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Pathology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Medical Pathology","Medical Sciences","Medicine and Health Sciences"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["© The Author"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://doi.org/10.25772/4GZ3-NH22","https://scholarscompass.vcu.edu/etd/25"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The primary aims of this study were to examine acquired genetic and epigenetic changes that occur in individuals with increasing age and to determine how these changes are influenced by genetic/environmental factors. Acquired genetic changes were assessed by determining the frequency and chromosomal contents of spontaneously occurring micronuclei in identical and fraternal twins. A total of 115 individuals (48 twin pairs and 19 singletons) were evaluated, ranging in age from 7 to 85 years. As expected, micronuclei frequencies, which are indicative of genomic damage, significantly increased with age (p<0.0001, r=0.446). The majority of micronuclei (32%) contained sex chromosomes and the frequency of sex chromosome-bearing micronuclei significantly increased with age (p<0.0001). The frequency of autosome-containing micronuclei was not significantly influenced by age or gender. However, some autosomes were seen more (chromosomes 4, 8, and 9) or less (chromosomes 17 and 22) frequently than expected by chance (p<0.05). An evaluation of the numerical contents of the sex chromosome-containing micronuclei and their corresponding binucleates showed that the majority of the binucleates had an abnormal chromosomal complement (either hypodiploid or hyperdiploid), with the subset of binucleates having a normal chromosomal complement decreasing with age for both the Y chromosome in males and the X chromosome in females. Model fitting, implemented in Mx, showed the variation in the frequency of micronuclei to be best explained by either additive genetic and unique environmental components, or common and unique environmental factors. Specific environmental exposures and health conditions that were shown to influence micronuclei frequencies, included: multivitamins, leafy green vegetables, fruit, vitamin E supplements, arthritis, heart disease, allergies, and alcohol. To assess acquired epigenetic changes, global methylation profiles of two identical twin pairs were compared and found to differ, indicating that individuals do develop alterations in their methylation profiles with age. Furthermore, the twin pair having a significant difference in their micronuclei frequencies and environmental exposures had more differences in their methylation pattern compared to the twin pair whose micronuclei frequencies and environmental factors did not differ. Overall, genetic and epigenetic changes were shown to occur with age and to be influenced by genetic and lifestyle factors."]},{"key":"dc:title","label":"Title","values":["Age-related genetic and epigenetic chromosomal changes: A twin study"]}]}],"canonical_facts":{"dc:contributor":["Colleen Jackson-Cook"],"dc:creator":["Jones, Kimberly"],"dc:date.available":["2014-12-11T08:00:00Z"],"dc:description.abstract":["The primary aims of this study were to examine acquired genetic and epigenetic changes that occur in individuals with increasing age and to determine how these changes are influenced by genetic/environmental factors. Acquired genetic changes were assessed by determining the frequency and chromosomal contents of spontaneously occurring micronuclei in identical and fraternal twins. A total of 115 individuals (48 twin pairs and 19 singletons) were evaluated, ranging in age from 7 to 85 years. As expected, micronuclei frequencies, which are indicative of genomic damage, significantly increased with age (p<0.0001, r=0.446). The majority of micronuclei (32%) contained sex chromosomes and the frequency of sex chromosome-bearing micronuclei significantly increased with age (p<0.0001). The frequency of autosome-containing micronuclei was not significantly influenced by age or gender. However, some autosomes were seen more (chromosomes 4, 8, and 9) or less (chromosomes 17 and 22) frequently than expected by chance (p<0.05). An evaluation of the numerical contents of the sex chromosome-containing micronuclei and their corresponding binucleates showed that the majority of the binucleates had an abnormal chromosomal complement (either hypodiploid or hyperdiploid), with the subset of binucleates having a normal chromosomal complement decreasing with age for both the Y chromosome in males and the X chromosome in females. Model fitting, implemented in Mx, showed the variation in the frequency of micronuclei to be best explained by either additive genetic and unique environmental components, or common and unique environmental factors. Specific environmental exposures and health conditions that were shown to influence micronuclei frequencies, included: multivitamins, leafy green vegetables, fruit, vitamin E supplements, arthritis, heart disease, allergies, and alcohol. To assess acquired epigenetic changes, global methylation profiles of two identical twin pairs were compared and found to differ, indicating that individuals do develop alterations in their methylation profiles with age. Furthermore, the twin pair having a significant difference in their micronuclei frequencies and environmental exposures had more differences in their methylation pattern compared to the twin pair whose micronuclei frequencies and environmental factors did not differ. Overall, genetic and epigenetic changes were shown to occur with age and to be influenced by genetic and lifestyle factors."],"dc:identifier":["https://doi.org/10.25772/4GZ3-NH22","https://scholarscompass.vcu.edu/etd/25"],"dc:rights":["© The Author"],"dc:subject":["Medical Pathology","Medical Sciences","Medicine and Health Sciences"],"dc:title":["Age-related genetic and epigenetic chromosomal changes: A twin study"],"thesis:degree_discipline":["Pathology"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy"]},"updated_at":"2026-07-24T05:53:18Z"}