What are Deletions?
A deletion is a chromosomal abnormality where a segment of DNA is missing. This results in the loss of one or more genes, which can disrupt normal development and cause genetic disorders.
- Small deletions may only affect a single gene.
- Large deletions can remove multiple genes and lead to more severe conditions.
Key Features
- Can occur on any chromosome and vary greatly in size.
- The effect depends on which genes are lost and how important they are for development.
- May be inherited from a parent or occur spontaneously during egg or sperm formation.
Common Health Implications
- Developmental delays and intellectual disabilities
- Physical birth defects (heart, facial, skeletal anomalies)
- Increased risk for certain syndromes (e.g., Cri-du-chat syndrome, 22q11.2 deletion syndrome, Williams syndrome)
How to Reduce the Risk
- Preimplantation Genetic Testing (PGT-SR or PGT-M) during IVF to detect embryos without deletions
- Genetic counseling to understand inheritance risk and options
- Prenatal testing (CVS or amniocentesis) for early detection in pregnancy