Ectopia

From Wikipedia, the free encyclopedia

In medicine an ectopia is a displacement or malposition of an organ of the body. Most ectopias are congenital but some may happen later in life.

• Ectopia lentis is the displacement of the crystalline lens of the eye
• Ectopia cordis is the displacement of the heart outside the body during fetal development
• Renal ectopia occurs when both kidneys occur on the same side of the body
• Ectopic pregnancy occurs when the fertilized egg implants anywhere other than the uterine wall
• Cardiac ectopy occurs when electrical signals for a heartbeat originate in the wrong part of the heart muscle.

In molecular biology the term ectopic is used for at least three purposes:

• ectopic recombination refers to recombination between sites, usually containing identical or similar sequences, at different locations in the genome, leading to deletions, insertions, or chromosomal crossovers
• a gene is ectopically expressed when it is expressed in an abnormal place.
• in transgenic experiments, ectopic integration indicates the insertion of the transgene at a site other than its natural chromosomal locus