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Genetics Library / Conditions / Trisomy X

CONDITION REFERENCE

Trisomy X

Information from MedlinePlus Genetics about this condition and how it can be inherited.

About this condition

Trisomy X, also called triple X syndrome or 47,XXX, is characterized by the presence of an additional X chromosome in each of a female's cells. Although females with this condition may be taller than average, this chromosomal change typically causes no unusual physical features. Most females with trisomy X have normal sexual development and are able to conceive children.

Trisomy X is associated with an increased risk of learning disabilities and delayed development of speech and language skills. Delayed development of motor skills (such as sitting and walking), weak muscle tone (hypotonia), and behavioral and emotional difficulties are also possible, but these characteristics vary widely. Seizures or kidney abnormalities occur in about 10 percent of affected females.

Source: MedlinePlus, National Library of Medicine. Source publication: 2022-03-01. Source review: 2022-02.

Inheritance

  • Not inherited

A condition can have several forms with different inheritance patterns. Each pattern may apply to a different gene or form of the condition.

Related genes

The source data used here does not list individual genes. Some conditions involve changes to chromosomes or have other causes.

YOUR DNA FILE

What can your DNA file tell you?

Your DNA file only includes the positions your test checked and reported. Consumer DNA kits usually test selected positions. Sequencing files can also leave out positions that were not reported or where the test could not give a result.

A variant missing from your file does not mean you tested negative for it. A ClinVar classification applies to a particular variant and the condition or finding it was reported for. It does not apply to everyone with that gene. An uncertain finding cannot establish a diagnosis.

BioDecode reads supported DNA files on your computer. It cannot fill gaps in your test, diagnose a condition or replace clinical testing.

Sources and dates

The source information on this page last changed on 2026-09-18.

MedlinePlus Source details

Open source record ↗

Source release: Fri, 18 Sep 2026 05:17:13 GMT
Source publication: 2022-03-01
Source review: 2022-02

SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a

About the library sources · Latest validated release · Record 0933c7313a58