A karyotype report describes the number and structure of your chromosomes. Below are the most common findings and what they mean.
Conditions a karyotype can detect
21Down syndrome
Trisomy 21: an extra chromosome 21.
18Edwards syndrome
Trisomy 18: an extra chromosome 18.
13Patau syndrome
Trisomy 13: an extra chromosome 13.
XXYKlinefelter syndrome
An extra X chromosome in males; the most common sex chromosome abnormality in males.
XTurner syndrome
One X chromosome missing in females.
9;22Chronic myelogenous leukaemia
The classic 9;22 translocation is diagnostic of this blood cancer.
Types of chromosome abnormalities
| Type | What it means | Examples / notes |
|---|---|---|
| Trisomy | An extra chromosome instead of a pair. | Down (21), Patau (13) and Edwards (18) syndromes; Klinefelter syndrome (XXY) and other extra sex chromosome conditions. |
| Monosomy | A missing chromosome. | Turner syndrome (single X) is the most common. Most other monosomies are not compatible with life and may cause miscarriage. |
| Deletions | Missing pieces of a chromosome. | Can affect the short or long arm; some are very small and hard to detect. |
| Duplications | Extra genetic material. | May appear on any chromosome, e.g. an extra band at a specific location. |
| Translocations | A piece of one chromosome attaches to another. | “Balanced” when no material is lost or gained; “unbalanced” when material is missing or extra. |
| Rearrangements | Material present but in an unusual location. | May occur with a duplication or deletion; interpretation can be challenging. |
Every result should be explained by a qualified genetic counsellor. Book a post-test counselling session to understand what your result means for you and your family.