Insights From Identical Twins

Overview

• Identical twins originate from a single fertilized egg, sharing the same genome.
• Differences between identical twins are attributed to environmental factors rather than genetics.
• Environmental influences are often reflected in the epigenome.

Nature and Nurture

• Twin studies help understand the interaction of genetics (nature) and environment (nurture).
• Researchers use twin studies to explore inherited traits versus learned traits.
• Classical twin studies are prevalent in Behavioral Genetics.
• Data from twins, raised together or apart, provide insights into the genetic and environmental roles in trait development.

Epigenome Differences

• Chromosome 3 pairs in twins show epigenetic differences with age.
• Older twins (50 years) have more divergent epigenetic tags compared to younger twins (3 years).

Twin Studies and Findings

• Twin studies reveal both genetic and environmental contributions to traits and diseases.
• Identical twins (share all genes) and fraternal twins (share half genes) provide a comparison for genetic influence.
• Examples:
  • Schizophrenia: 50% of identical twins share the disease, compared to 10-15% of fraternal twins.
  • Reading disabilities like dyslexia show a strong genetic component.
  • Diseases like arthritis are more influenced by the environment.

Environmental Influence

• As twins age, their environments diverge more, offering insights into environmental impacts on traits.
• Differences in disease occurrence among twins are analyzed for environmental versus genetic causes.

Importance of Large Studies

• Large twin studies can pinpoint molecular mechanisms of diseases.
• Enable understanding of environmental impact and genetic predispositions, aiding in prevention and treatment strategies.

References

• Cited studies provide evidence and examples of epigenetic differences and twin discordance in diseases.

Additional Resources

• References and external resources are available for further study and verification of information.

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