Karyotyping

What is the Karyotyping test?

Karyotyping is a specialised genetic test that examines the number, size and structure of chromosomes within a person’s cells. Chromosomes carry genetic information, and abnormalities in their structure or number can lead to developmental, reproductive, or medical conditions.

The test is performed on cultured cells, usually from a blood sample, allowing laboratory specialists to visualise chromosomes under a microscope. This detailed analysis can identify missing, extra, or rearranged chromosomes.

Karyotyping is a foundational test in clinical genetics and is widely used in reproductive medicine, haematology, and prenatal investigations.

Why do I need a Karyotyping test?

Karyotyping is requested when there is suspicion of a chromosomal abnormality that cannot be detected by routine blood tests.

You may need a Karyotyping test if you:

• Have unexplained infertility
• Have recurrent miscarriages
• Have a family history of genetic conditions
• Have abnormal prenatal screening results
• Have developmental delay or congenital abnormalities
• Are being assessed for chromosomal syndromes
• Have certain blood or bone marrow disorders

Clinical situations where karyotyping is commonly used include:

• Recurrent pregnancy loss
• Turner syndrome, Down syndrome and related conditions
• Balanced or unbalanced chromosomal translocations
• Certain haematological malignancies

Benefits of the Karyotyping test

• Detects chromosomal abnormalities
  Identifies numerical and structural changes.
• Supports fertility investigations
  Useful in unexplained infertility and miscarriage.
• Guides reproductive planning
  Helps assess genetic risks.
• Clinically established genetic test
  Used worldwide in genetic diagnostics.
• Identifies inherited or acquired changes
  Relevant in both congenital and acquired conditions.
• Supports prenatal and postnatal assessment
  Used across life stages.
• Provides definitive genetic information
  Results do not change over time.
• Informs specialist referral and counselling
  Supports genetic counselling decisions.

Step by step – how the test works

You can access Karyotyping testing UK-wide through two options:

1. Clinic appointment
   Attend your nearest UK clinic where a healthcare professional will take your blood sample.
2. At-home or hotel visit (£60 extra)
   A qualified phlebotomist can visit your home or hotel to collect the blood sample.

The sample is sent to a specialist genetics laboratory. Because cell culture is required, results take longer than routine blood tests.

Your results explained

Normal karyotype

Shows the expected number and structure of chromosomes, indicating no detectable chromosomal abnormalities.

Typical UK result:

• 46,XX (female) or 46,XY (male)

Numerical chromosome abnormalities

Indicate extra or missing chromosomes, such as trisomies or monosomies.

Examples include:

• Trisomy 21 (Down syndrome)
• Turner syndrome (45,X)

Structural chromosome abnormalities

Show rearrangements such as translocations, deletions, or inversions, which may affect fertility or health.

Results should always be interpreted by a specialist in genetics.