Difference between revisions of "Trisomy X"

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(Introduction)
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* ''' Root length in the permanent teeth of women with an additional X chromosome (47,XXX females)'''<ref name=PMID20568965><pubmed>20568965</pubmed></ref> "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."
 
* ''' Root length in the permanent teeth of women with an additional X chromosome (47,XXX females)'''<ref name=PMID20568965><pubmed>20568965</pubmed></ref> "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."
 
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==Prenatal Diagnosis==
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The most common prenatal diagnosis is by either amniocentesis or chorionic villi sampling.
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[[File:Amniocentesis.jpg]] [[File:Cvs.jpg]]
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:'''Links:'''[[Amniocentesis]] | [[Chorionic villus sampling]]
  
 
==Physical Features==
 
==Physical Features==

Revision as of 09:53, 28 November 2011

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

Introduction

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).


Alternative names: Triplo X syndrome, Trisomy X, 47,XXX, XXX syndrome


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

  • A review of trisomy X (47,XXX)[1] "Trisomy X is a sex chromosome anomaly with a variable phenotype caused by the presence of an extra X chromosome in females (47,XXX instead of 46,XX). It is the most common female chromosomal abnormality, occurring in approximately 1 in 1,000 female births."
  • Root length in the permanent teeth of women with an additional X chromosome (47,XXX females)[2] "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."

Prenatal Diagnosis

The most common prenatal diagnosis is by either amniocentesis or chorionic villi sampling.

Amniocentesis.jpg Cvs.jpg


Links:Amniocentesis | Chorionic villus sampling

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[1]

References

  1. 1.0 1.1 <pubmed>20459843</pubmed>
  2. <pubmed>20568965</pubmed>

Reviews

<pubmed>20459843</pubmed> <pubmed>17062147</pubmed>

Articles

<pubmed> 19732877</pubmed>

Search PubMed

Search Pubmed: Trisomy X

External Links

External Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name. Links to any external commercial sites are provided for information purposes only and should never be considered an endorsement. UNSW Embryology is provided as an educational resource with no clinical information or commercial affiliation.


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Cite this page: Hill, M.A. (2019, July 23) Embryology Trisomy X. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Trisomy_X

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© Dr Mark Hill 2019, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G