Turner Syndrome and X Chromosome Defects

Since Turner syndrome and X chromosome defects are related, it's a good idea to have a basic understanding of the X chromosome problems that can cause the disorder. A woman with Turner syndrome will have one of three X chromosome defects, which include: defect of the X chromosome in all cells, absence of the X chromosome in some cells, and absence of the X chromosome in all cells.

 

An Overview of Turner Syndrome and X Chromosome Defects

The cause of Turner syndrome is a partial or complete absence of one of the two X chromosomes (sex chromosomes).
 
A woman with Turner syndrome will have one of three X chromosome problems:
 

Turner Syndrome and X Chromosome Defects: The Specifics

A third cause of Turner syndrome involves X chromosome defects, rather than complete loss. For example, one X chromosome may be fragmented, have portions deleted, or have other structural problems, such as ring formation preventing the normal expression of X chromosome genes.
 

Symptoms of Turner Syndrome With X Chromosome Defects

In a woman having one normal and one defective X chromosome, the symptoms vary widely.
 
A small deletion on the X chromosome may result in a single Turner syndrome feature, such as ovarian failure or short stature, and no other effects. Larger deletions or deletions on the X chromosome, affecting critical areas regulating the whole chromosome, may result in a full spectrum of Turner syndrome features.
 
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Written by/reviewed by: Arthur Schoenstadt, MD
Last reviewed by: Arthur Schoenstadt, MD