Notice: Fetal sex determination is strictly prohibited and illegal under the PCPNDT Act, 1994. DNA Labs India does not perform sex disclosure under any circumstances.
When is Karyotyping Recommended? A Clinical Guide
Quick Summary
- Sample Required: Peripheral blood (or amniotic fluid/chorionic villi for prenatal)
- Fasting Rules: No fasting required
- Turnaround Time: 2–4 weeks
- Base Cost: [Insert Current 2026 Price]
PCPNDT Notice: This article discusses prenatal genetic testing, which is regulated under the Pre-Conception and Pre-Natal Diagnostic Techniques (PCPNDT) Act in India. All tests are performed in compliance with applicable laws.
What is Karyotyping?
Karyotyping is a cytogenetic test that examines the number, size, and structure of chromosomes in a sample of cells. It is used to detect chromosomal abnormalities—both numerical (e.g., trisomy, monosomy) and structural (e.g., translocations, deletions). The test is performed on dividing cells, typically from blood, bone marrow, or prenatal samples such as amniotic fluid or chorionic villi.
When is Karyotyping Recommended?
Karyotyping is recommended in several clinical scenarios to identify or confirm chromosomal disorders. The following are the primary indications:
- Infants and Children with Suspected Chromosomal Abnormalities: When a child presents with developmental delays, dysmorphic features, or congenital anomalies that suggest a chromosomal cause, karyotyping is often the first-line diagnostic test.
- Adults with Unexplained Symptoms: Some chromosomal conditions, such as Klinefelter syndrome (47,XXY) or mosaic trisomy, may remain undiagnosed until puberty or adulthood. Karyotyping can confirm these diagnoses.
- Infertility: Both male and female infertility can be linked to chromosomal abnormalities. For example, a woman with Turner syndrome (45,X) or a man with Klinefelter syndrome may have no obvious symptoms until attempting conception.
- Prenatal Testing: Karyotyping is performed on fetal cells obtained via amniocentesis or chorionic villus sampling (CVS) when there is an increased risk of aneuploidy, a family history of chromosomal rearrangements, or abnormal ultrasound findings. It is a diagnostic test, unlike NIPT which is a screening test.
- Stillbirth: After a stillbirth, karyotyping of fetal tissue can help determine if a chromosomal abnormality was the cause, providing closure and informing future reproductive planning.
- Recurrent Miscarriages: Parental karyotyping is recommended for couples who have experienced two or more miscarriages. Chromosomal rearrangements (e.g., balanced translocations) in either parent can lead to recurrent pregnancy loss.
- Leukemia and Other Hematologic Malignancies: Karyotyping of bone marrow or blood cells is used to identify specific chromosomal abnormalities, such as the Philadelphia chromosome (t(9;22)) in chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL). This aids in diagnosis, prognosis, and treatment planning.
Karyotyping in Specific Clinical Scenarios
The following table summarizes the common indications, sample types, and clinical contexts for karyotyping:
| Indication | Sample Type | Clinical Scenario |
|---|---|---|
| Prenatal diagnosis | Amniotic fluid / CVS | Abnormal ultrasound, positive NIPT, family history |
| Recurrent miscarriage | Peripheral blood (both parents) | Two or more pregnancy losses |
| Infertility | Peripheral blood | Unexplained infertility, suspected gonadal dysgenesis |
| Stillbirth | Fetal tissue | Post-mortem evaluation |
| Leukemia | Bone marrow / peripheral blood | Diagnosis and monitoring of hematologic malignancies |
Karyotyping vs. Chromosomal Microarray
While karyotyping provides a global view of chromosomes, chromosomal microarray (CMA) offers higher resolution for detecting submicroscopic copy number variants. The choice depends on the clinical indication:
| Feature | Karyotyping | Chromosomal Microarray |
|---|---|---|
| Resolution | 5–10 Mb | 50–100 kb |
| Detects | Aneuploidy, large deletions/duplications, balanced rearrangements | Copy number variants, loss of heterozygosity |
| Turnaround Time | 2–4 weeks | 1–2 weeks |
| Cost | [Insert Current 2026 Price] | [Insert Current 2026 Price] |
How is Karyotyping Performed?
The test requires a sample of dividing cells. For blood samples, lymphocytes are stimulated to divide in culture. For prenatal samples, cells from amniotic fluid or chorionic villi are cultured. The cells are then arrested in metaphase, stained, and photographed under a microscope. Chromosomes are arranged in a standard karyotype format for analysis.
Sample Requirements: Peripheral blood (2–5 mL in a heparinized tube) or prenatal samples (amniotic fluid, CVS). No fasting is required.
Understanding Your Results
Results are reported as a karyotype formula, e.g., 46,XY (normal male) or 47,XX,+21 (Down syndrome). A medical geneticist will interpret the findings and provide counseling regarding implications for the individual and family.
Where to Get Karyotyping Done in India
DNA Labs India is a leading molecular diagnostic company dedicated to making a difference in patients' lives through the discovery and commercialization of transformative tests to assess a person's risk of developing disease, guide treatment decisions, and assess the risk of disease progression and recurrence.
How to Book a Test
Visit the website www.dnalabsindia.com for any DNA test. We can help you get your DNA test done. We have services in over 180 cities in India. Call us on the below-mentioned numbers or visit our sample collection centre near your location.
It is safe, secure, confidential, and best of all, an easy process. Avoid the hassle of taking a day off from work, traffic, and pollution. Our highly qualified sample collector will visit your home for sample collection as per your convenient time slot booked by you.
To know more about the test or to schedule a test, contact us on the following numbers for major metropolitan cities:
- New Delhi: (011) 40849842
- Mumbai: (022) 48937160
- Kolkata: (033) 40836441
- Chennai: (044) 48137110
- Bangalore: (080) 45684079
- Hyderabad: (040) 49171772
- Ahmedabad: (079) 49107674
Notice: Fetal sex determination is strictly prohibited and illegal under the PCPNDT Act, 1994. DNA Labs India does not perform sex disclosure under any circumstances.