Karyotyping Analysis

Function

Karyotyping Analysis is a cytogenetic test used to examine the full complement of chromosomes in a person's cells. It maps the 22 pairs of autosomes and the pair of sex chromosomes to identify abnormalities in number or structure. The process involves culturing cells (usually lymphocytes), arresting them during metaphase, staining them, and photographing them under a microscope to create a 'karyogram'.

Why it is Ordered

Karyotyping is a foundational tool in clinical genetics used for:

• Prenatal Screening: Detecting chromosomal disorders like Down Syndrome in a fetus.
• Infertility Investigations: Evaluating couples with recurrent pregnancy loss or primary amenorrhea.
• Developmental Delays: Assessing children with unexplained physical or cognitive delays.
• Oncology: Identifying specific chromosomal translocations (e.g., the Philadelphia chromosome) that guide treatment in leukemias.

Associated Conditions

• Trisomy 21 (Down Syndrome): An extra copy of chromosome 21.
• Turner Syndrome (45,X): A missing X chromosome in females.
• Klinefelter Syndrome (47,XXY): An extra X chromosome in males.
• Balanced Translocations: Structural rearrangements that may cause infertility or risk to offspring.
• Trisomy 18 (Edwards Syndrome) and Trisomy 13 (Patau Syndrome): Severe developmental conditions.