What are Duplications?

A duplication is a chromosomal abnormality where a segment of DNA is copied one or more times, resulting in extra genetic material.

  • Small duplications may involve a single gene.
  • Large duplications can contain multiple genes, potentially affecting many biological processes.

Key Features

  • Can occur on any chromosome and vary in size.
  • May be inherited from a parent who is a balanced carrier or arise spontaneously during egg or sperm formation.
  • The impact depends on the size and location of the duplicated segment.

Common Health Implications

  • Developmental delays and intellectual disabilities
  • Physical abnormalities (e.g., facial differences, heart defects)
  • Certain syndromes, such as Charcot–Marie–Tooth disease type 1A, MECP2 duplication syndrome, and Pallister–Killian syndrome

How to Reduce the Risk

  • Preimplantation Genetic Testing for Structural Rearrangements (PGT-SR) during IVF to identify embryos without duplications
  • Genetic counseling to understand inheritance patterns and reproductive options
  • Prenatal testing (CVS or amniocentesis) for early detection in pregnancy