Difference between revisions of "2011 Group Project 3"

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Klinefelter's syndrome usually presents with a few standard clinical abnormalities.  Affected men can can have reduced fertility and hypogonadism.  However, a high proportion of affected men may not show any symptoms and the severity of the disorder differs greatly from person to person.  It is thought to be one of the most common conditions caused by non-disjunction<ref><pubmed>17062147</pubmed></ref>.
 
Klinefelter's syndrome usually presents with a few standard clinical abnormalities.  Affected men can can have reduced fertility and hypogonadism.  However, a high proportion of affected men may not show any symptoms and the severity of the disorder differs greatly from person to person.  It is thought to be one of the most common conditions caused by non-disjunction<ref><pubmed>17062147</pubmed></ref>.
  
This disorder was first described by Harry F. Klinefelter in 1942 <ref>Klinefelter HF, Reifenstein EC & Albright F. Syndrome characterized by gynecomastia, aspermatogenesis without a-Leydigism, and increased excretion of follicle-stimulating hormone. American Journal of Clinical Dermatology 1942; 2: 615–627.</ref>.  He describes a disorder characterised by gynecomastia and a very specific type of hypogonadism, as well as an absence of spermatogenesis.
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This disorder was first described by Harry F. Klinefelter in 1942 <ref>Klinefelter HF, Reifenstein EC & Albright F. ''Syndrome characterized by gynecomastia, aspermatogenesis without a-Leydigism, and increased excretion of follicle-stimulating hormone.'' American Journal of Clinical Dermatology 1942; 2: 615–627.</ref>.  He describes a disorder characterised by gynecomastia and a very specific type of hypogonadism, as well as an absence of spermatogenesis.
  
 
==History==
 
==History==

Revision as of 11:29, 15 August 2011

Note - This page is an undergraduate science embryology student group project 2011.
2011 Projects: Turner Syndrome | DiGeorge Syndrome | Klinefelter's Syndrome | Huntington's Disease | Fragile X Syndrome | Tetralogy of Fallot | Angelman Syndrome | Friedreich's Ataxia | Williams-Beuren Syndrome | Duchenne Muscular Dystrolphy | Cleft Palate and Lip




Kleinfelter Syndrome

Introduction

Klinefelter's syndrome is a condition wherein a male has an extra X chromosome. Typically, men and women have two sex chromosomes, women have two X chromosomes (46,XX), while men have an X and Y chromosome (46,XY). '46' refers to the total number of chromosomes present including both autosomes and sex chromosomes. However, men with Klinefelter's syndrome have three sex chromosomes (47,XXY) due to a process known as non-disjunction[1].

In some very rare cases there are two or more extra copies of the X chromosome present (48,XXXY, or 49,XXXXY). This generally results in more prominent clinical features. In approximately 20% of cases, 46,XY/47,XXY mosaicism can occur[2]. This refers to the situation where the extra chromosome is only present in some cells, this is due to errors occurring during mitosis.


Klinefelter's syndrome usually presents with a few standard clinical abnormalities. Affected men can can have reduced fertility and hypogonadism. However, a high proportion of affected men may not show any symptoms and the severity of the disorder differs greatly from person to person. It is thought to be one of the most common conditions caused by non-disjunction[3].

This disorder was first described by Harry F. Klinefelter in 1942 [4]. He describes a disorder characterised by gynecomastia and a very specific type of hypogonadism, as well as an absence of spermatogenesis.

History

Epidemiology

Frequency of specific karyotypes in Danish population which include Klinefelter Syndrome

--z3289991 10:15, 13 August 2011 (EST)

Signs and Symptoms

Etiology

Pathogenesis

Treatment

Other Similar Defects

Current Research

Glossary

References

  1. <pubmed>17062147</pubmed>
  2. <pubmed>21397196</pubmed>
  3. <pubmed>17062147</pubmed>
  4. Klinefelter HF, Reifenstein EC & Albright F. Syndrome characterized by gynecomastia, aspermatogenesis without a-Leydigism, and increased excretion of follicle-stimulating hormone. American Journal of Clinical Dermatology 1942; 2: 615–627.



2011 Projects: Turner Syndrome | DiGeorge Syndrome | Klinefelter's Syndrome | Huntington's Disease | Fragile X Syndrome | Tetralogy of Fallot | Angelman Syndrome | Friedreich's Ataxia | Williams-Beuren Syndrome | Duchenne Muscular Dystrolphy | Cleft Palate and Lip