Difference between revisions of "Trisomy X"

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Table data from Tartaglia NR, etal., 2010<ref><pubmed>20459843</pubmed></ref>
== References ==  
== References ==  

Revision as of 14:45, 15 December 2010

Notice - Mark Hill
Currently this page is only a template and will be updated (this notice removed when completed).


Trisomy X is a caused by the presence of an extra X chromosome in females (47,XXX instead of 46,XX). This is also the most common female chromosomal abnormality, occurring in approximately 1 in 1,000 female births.

Other abnormalities of chromosome number include: female tetrasomy X (quadruple X, or 48, XXXX) a rare chromosomal disorder and male Klinefelter syndrome, the presence of an additional X chromosome (47, XXY or XXY).

Genetic Links: genetic abnormalities | maternal age | Trisomy 21 | Trisomy 18 | Trisomy 13 | Trisomy X | trisomy mosaicism | Monosomy | Fragile X | Williams | Alagille | Philadelphia chromosome | mitochondria | VACTERL | hydatidiform mole | epigenetics | Prenatal Diagnosis | Neonatal Diagnosis | meiosis | mitosis | International Classification of Diseases | genetics

| Genital System - Abnormalities

Some Recent Findings

  • Root length in the permanent teeth of women with an additional X chromosome (47,XXX females)[1] "Increased enamel thickness in the teeth of 47,XXX females is apparently caused by the active enamel gene in all X chromosomes having no increased influence on crown dentin formation. These results in 47,XXX females indicate an increase in root dentin development, at least in the mandible, which together with the data on crown formation reflects a continuous long-lasting effect of the X chromosome on dental development."

Physical Features

Feature Estimated frequency based on current available data
Tall stature >75th percentile 80-89%
Epicanthal folds 32-46%
Clinodactyly 42-65%
Hypotonia in infancy 55-71%
Genitourinary malformations 5-16%
Seizure disorder 11-15%
Intention tremor 6-20%
Congenital hip dysplasia 2-12%
Constipation/Abdominal pains 12-45%
Premature ovarian failure unknown

Table data from Tartaglia NR, etal., 2010[2]


  1. <pubmed>20568965</pubmed>
  2. <pubmed>20459843</pubmed>




<pubmed> 19732877</pubmed>

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Cite this page: Hill, M.A. (2020, February 21) Embryology Trisomy X. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Trisomy_X

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