Peripheral Blood Karyotype

A karyotype is a microscope-level analysis of all of a person's chromosomes, prepared by culturing cells from a peripheral blood sample. It detects numerical chromosome abnormalities and larger structural rearrangements such as translocations, deletions, and duplications. The test is commonly requested in the work-up of infertility, recurrent pregnancy loss, developmental concerns, or a family history of chromosomal conditions. An expedited STAT option is available when a faster result is needed.

Karyotyping examines the full set of an individual's chromosomes — their number, size, and structure — under the microscope. White blood cells from a peripheral blood sample are cultured in the laboratory, arrested at the stage of cell division where chromosomes are most condensed and visible, then stained and arranged into a karyogram for analysis. The test reliably detects numerical abnormalities (such as an extra or missing chromosome) and structural abnormalities visible at the chromosomal level, including balanced and unbalanced translocations, large deletions and duplications, inversions, and ring chromosomes. These findings are particularly relevant in the investigation of infertility and recurrent miscarriage, where a balanced chromosomal rearrangement in one partner can be the underlying cause, and in evaluating individuals with developmental or congenital features or a relevant family history. The laboratory offers a standard turnaround as well as an expedited STAT karyotype for situations where the result is needed more quickly. Because chromosome analysis requires living cells to be cultured, a minimum processing time is unavoidable. Karyotyping complements molecular methods such as microarray, which resolves smaller submicroscopic changes that a karyotype cannot detect; the laboratory advises on the most appropriate method for the clinical question.