Genetic Factors in Health
Genetics plays a critical role in health outcomes, influencing disease risk, treatment options, and preventive strategies. Approximately 40% of diseases have a genetic component3, as suggested by a study involving 560 common conditions.
Currently, there are 7,000 types of rare diseases to name and over 80% are genetic with 70% of these starting in childhood4. In the Asia-Pacific, the prevalence of rare diseases is significant, affecting around 258 million people5, with half being children.
Carriers
A genetic carrier is an individual who has one working copy and one non-working copy of a gene, typically associated with autosomal recessive or sex-linked conditions. Carriers usually do not display symptoms of the disease themselves but can pass the non-working allele to their offspring.
Many people are carriers of genetic mutations without realizing it. For example, about 36% of the global population (2.7 billion people) are healthy carriers of at least one mutation that can cause autosomal recessive inherited retinal diseases6.
If both parents are carriers of the same condition, there is a 25% chance that each child will inherit two non-working copies and express the disease, a 50% chance that each child will be a carrier like the parents, and a 25% chance that each child will inherit two working copies and neither be affected nor a carrier.
Lifestyle and Epigenetics: How Environment Shapes Genes
Epigenetics is the study of how environmental factors, including lifestyle choices, influence gene expression without altering the DNA sequence itself. This field has shown that diet, exercise, stress, and other habits can significantly impact health outcomes by modifying epigenetic marks such as DNA methylation and histone modifications.
By understanding how lifestyle choices affect epigenetics, individuals can make informed decisions to improve their health outcomes and reduce genetic risks.
References
- Nature news. https://www.nature.com/scitable/topicpage/inheritance-of-traits-by-offspring-follows-predictable-6524925/
- Loewe, L. (2008) Genetic mutation. Nature Education 1(1):113
- Stallard, T. (2023) Rare disease care across asia pacific, Sandpiper.
- Hlawulani (2019) New Scientific Paper confirms 300 million people living with a rare disease worldwide, Rare Diseases International.
- Pesheva, E. (2023) Researchers able to determine the effects of genes and environment in 560 common conditions, Harvard Gazette.
- Hanany, M., Rivolta, C., & Sharon, D. (2020). Worldwide carrier frequency and genetic prevalence of autosomal recessive inherited retinal diseases. Proceedings of the National Academy of Sciences, 117(5), 2710–2716. https://doi.org/10.1073/pnas.1913179117
- Abdul, Q. A., Yu, B. P., Chung, H. Y., Jung, H. A., & Choi, J. S. (2017). Epigenetic modifications of gene expression by lifestyle and environment. Archives of Pharmacal Research, 40(11), 1219–1237. https://doi.org/10.1007/s12272-017-0973-3
- Alegría-Torres, J. A., Baccarelli, A., & Bollati, V. (2011). Epigenetics and Lifestyle. Epigenomics, 3(3), 267–277. https://doi.org/10.2217/epi.11.22
- CDC. (2025, January 31). Epigenetics, Health, and Disease. Genomics and Your Health. https://www.cdc.gov/genomics-and-health/epigenetics/index.html
- Advantages of NGS Over Other Molecular Methods. (2020). Illumina.com. https://sapac.illumina.com/science/technology/next-generation-sequencing/beginners/advantages.html
- UF scientists test mouthwash method of collecting DNA – UF Health. (2023). Ufhealth.org. https://ufhealth.org/news/2002/uf-scientists-test-mouthwash-method-collecting-dna
- Zayats, T., Young, T. L., Mackey, D. A., Malecaze, F., Calvas, P., & Guggenheim, J. A. (2009). Quality of DNA Extracted from Mouthwashes. PLoS ONE, 4(7). https://doi.org/10.1371/journal.pone.0006165
- Lelieveld, S. H., Spielmann, M., Mundlos, S., Veltman, J. A., & Gilissen, C. (2015). Comparison of Exome and Genome Sequencing Technologies for the Complete Capture of Protein-Coding Regions. Human Mutation, 36(8), 815–822. https://doi.org/10.1002/humu.22813
- Zhao, Y., Fang, L. T., Shen, T., Choudhari, S., Talsania, K., Chen, X., Shetty, J., Kriga, Y., Tran, B., Zhu, B., Chen, Z., Chen, W., Wang, C., Jaeger, E., Meerzaman, D., Lu, C., Idler, K., Ren, L., Zheng, Y., & Shi, L. (2021). Whole genome and exome sequencing reference datasets from a multi-center and cross-platform benchmark study. Scientific Data, 8(1). https://doi.org/10.1038/s41597-021-01077-5
- Barbitoff, Y. A., Polev, D. E., Glotov, A. S., Serebryakova, E. A., Shcherbakova, I. V., Kiselev, A. M., Kostareva, A. A., Glotov, O. S., & Predeus, A. V. (2020). Systematic dissection of biases in whole-exome and whole-genome sequencing reveals major determinants of coding sequence coverage. Scientific Reports, 10(1). https://doi.org/10.1038/s41598-020-59026-y
