Chromosomal Disorders & Karyotyping

Causes & Risk Factors

Chromosomal abnormalities can be inherited from a parent (who may be an unaffected carrier of a balanced rearrangement) or can arise sporadically during egg, sperm, or early embryo formation:

•  Parental chromosomal rearrangement — a parent carrying a balanced chromosomal rearrangement may be unaffected personally but at increased risk of pregnancies with an unbalanced rearrangement.

•  Advanced maternal age — increases the likelihood of sporadic chromosome-number abnormalities such as trisomy conditions.

•  Spontaneous (de novo) chromosomal change — many chromosomal abnormalities arise newly, without either parent carrying the change.

•  Family history of a chromosomal condition or unexplained developmental disorder.

Symptoms & When to Test

Karyotyping is considered in several distinct clinical scenarios rather than for a single symptom pattern.

•  Recurrent pregnancy loss

•  Infertility, in either partner

•  Suspected chromosomal abnormality based on clinical features or prior test results

•  Certain congenital abnormalities identified at or after birth

•  Selected disorders of sexual development

When Should You Consider Testing?

Karyotyping is generally considered when there is a specific clinical indication — recurrent pregnancy loss, unexplained infertility, congenital abnormalities, or ambiguous findings on prenatal or postnatal evaluation — rather than as a routine or general screening test.

Why Tests Are Combined

Karyotyping provides a broad, whole-chromosome overview but has limited resolution for very small chromosomal changes — this is why it is often used as a first step, with chromosomal microarray or targeted molecular testing added when a more detailed or specific answer is needed.

In recurrent pregnancy loss or infertility evaluation, karyotyping is typically combined with other investigations (hormonal, autoimmune, or additional genetic testing) because chromosomal factors are only one of several possible contributing causes.

The choice of technique — karyotype alone, or karyotype plus microarray or targeted testing — depends on the specific clinical question being asked, and is best guided by your treating specialist or genetic counsellor.

Tests Available at NPL

Most reproductive hormone and genetic tests do not require fasting. However, some tests have specific timing requirements (such as a particular day of the menstrual cycle), and if other tests are ordered at the same time, fasting may be required for those investigations. Please follow the preparation and timing instructions provided by your doctor or NPL.

Home Sample Collection

NPL offers convenient home sample collection for Chromosomal Disorders & Karyotyping blood tests, so you don't need to visit a lab in person.

→ Book your test online, via the NPL app, or by calling +977 1 5970147 and select a convenient time slot for home sample collection.

→ A certified and experienced NPL phlebotomist visits your home at the scheduled time, following strict hygiene and safety protocols.

→ Your sample is transported under controlled, monitored conditions to NPL's NABL ACCREDITED UNDER ISO 15189:2022 laboratory for processing.

→ Your digital report is delivered securely to your phone or email, along with access to download and share it as needed.

When to See a Doctor

•  Recurrent pregnancy loss

•  Unexplained infertility in either partner

•  Congenital abnormality identified in a child

•  Suspected disorder of sexual development

•  Family history of a known chromosomal condition