karyotype

Full Definition

A laboratory analysis that examines the complete set of chromosomes from a cell, arranged in pairs according to size and structure to detect chromosomal abnormalities. In prenatal diagnosis, karyotyping is performed on cells obtained through amniocentesis, CVS, or cordocentesis to identify numerical abnormalities (like trisomies) or structural rearrangements. Traditional karyotyping requires cell culture and takes 1-2 weeks for results, though rapid methods can provide preliminary results sooner.

Usage

Usage note: Results typically reported as numerical notation (e.g., 46,XX or 47,XY,+21).

In Context

• "Fetal karyotype revealed normal 46,XY chromosomal composition." — genetic laboratory report
• "Rapid karyotype analysis was requested due to advanced maternal age." — requisition form