Heteroplasmy - Revision history

J at 22:18, 20 January 2009

2009-01-20T22:18:02Z

J at 22:17, 20 January 2009

2009-01-20T22:17:54Z

J at 22:15, 20 January 2009

2009-01-20T22:15:28Z

New page

<p><font color="#000000"><strong>Heteroplasmy</strong> is the presence of a mixture of more than one type of an organellar genome (mitochondrial DNA (mtDNA) or plastid DNA) within a cell or individual. Since every eukaryotic cell contains many hundreds of mitochondria with hundreds of copies of mtDNA, it is possible and indeed very frequent for mutations to affect only some of the copies, while the remaining ones are unaffected.</font></p>
<p><font color="#000000">Symptoms of severe heteroplasmic mitochondrial disorders frequently do not appear until adulthood because many cell divisions and a lot of time is required for a cell to receive enough mitochondria containing the mutant alleles to cause symptoms. An example of this phenomenon is Leber optic atrophy. Individuals with this condition often do not experience vision difficulties until they have reached adulthood.</font></p>
<p><font color="#000000">The incidence of heteroplasmy in human mtDNA is unknown, as the number of individuals who have been subjected to mtDNA testing for reasons other than the diagnosis of mitochondrial disorders is small. One notable example of an otherwise healthy individual whose heteroplasmy was discovered incidentally is Nicholas II of Russia, whose heteroplasmy (and that of his brother) served to convince Russian authorities of the authenticity of his remains.<sup id="cite_ref-0" class="reference"><font size="2"><span>[</span>1<span>]</span></font></sup></font></p>
<p><font color="#000000" size="2"></font></p>
<h2><span class="mw-headline"><font color="#000000">References</font></span></h2>
<div class="references-small">
<ol class="references">
<li id="cite_note-0"><font color="#000000"><strong>^</strong> Mitochondrial DNA sequence heteroplasmy in the Grand Duke of Russia Georgij Romanov establishes the authenticity of the remains of Tsar Nicholas II</font></li>
</ol>
</div>
<p><a id="See_also" name="See_also"><font color="#0066cc"></font></a></p>
<h2><span class="mw-headline">See also</span></h2>
<ul>
<li><a title="Homoplasmy" href="/wiki/Homoplasmy"><font color="#0066cc">homoplasmy</font></a></li>
<li><a title="Microheteroplasmy" href="/wiki/Microheteroplasmy"><font color="#0066cc">microheteroplasmy</font></a></li>
<li><a title="Paternal mtDNA transmission" href="/wiki/Paternal_mtDNA_transmission"><font color="#0066cc">Paternal mtDNA transmission</font></a></li>
</ul>
<div id="stub" class="boilerplate metadata">
<table style="BACKGROUND-COLOR: transparent" cellspacing="0" cellpadding="0">
<tbody>
<tr>
<td><a class="image" title="AlphaHelixSection.svg" href="/wiki/File:AlphaHelixSection.svg"></a></td>
<td> </td>
</tr>
</tbody>
</table>
</div>

@@ Line 11: / Line 11: @@
 </ol>
 </div>
-<p><a id="See_also" name="See_also"><font color="#0066cc"></font></a></p>
+<p>&nbsp;</p>
 <h2><span class="mw-headline">See also</span></h2>
 <ul>

@@ Line 1: / Line 1: @@
-<p><font color="#000000"><strong>Heteroplasmy</strong> is the presence of a mixture of more than one type of an organellar genome (mitochondrial DNA (mtDNA) or plastid DNA) within a cell or individual. Since every eukaryotic cell contains many hundreds of mitochondria with hundreds of copies of mtDNA, it is possible and indeed very frequent for mutations to affect only some of the copies, while the remaining ones are unaffected.</font></p>
+<p><font color="#000000"><strong>Heteroplasmy</strong> is the presence of a mixture of more than one type of an organellar genome (mitochondrial DNA (mtDNA) or plastid DNA) within a cell or individual.&nbsp;<br />
-<p><font color="#000000">Symptoms of severe heteroplasmic mitochondrial disorders frequently do not appear until adulthood because many cell divisions and a lot of time is required for a cell to receive enough mitochondria containing the mutant alleles to cause symptoms. An example of this phenomenon is Leber optic atrophy. Individuals with this condition often do not experience vision difficulties until they have reached adulthood.</font></p>
+Since every eukaryotic cell contains many hundreds of mitochondria with hundreds of copies of mtDNA, it is possible and indeed very frequent for mutations to affect only some of the copies, while the remaining ones are unaffected.</font></p>
-<p><font color="#000000">The incidence of heteroplasmy in human mtDNA is unknown, as the number of individuals who have been subjected to mtDNA testing for reasons other than the diagnosis of mitochondrial disorders is small. One notable example of an otherwise healthy individual whose heteroplasmy was discovered incidentally is Nicholas II of Russia, whose heteroplasmy (and that of his brother) served to convince Russian authorities of the authenticity of his remains.<sup id="cite_ref-0" class="reference"><font size="2"><span>[</span>1<span>]</span></font></sup></font></p>
+<p><font color="#000000">Symptoms of severe heteroplasmic mitochondrial disorders frequently do not appear until adulthood because many cell divisions and a lot of time is required for a cell to receive enough mitochondria containing the mutant alleles to cause symptoms. An example of this phenomenon is [[Leber optic atrophy]]. Individuals with this condition often do not experience vision difficulties until they have reached adulthood.</font></p>
 <p><font color="#000000" size="2"></font></p>
 <h2><span class="mw-headline"><font color="#000000">References</font></span></h2>
 <div class="references-small">
 <ol class="references">
-     <li id="cite_note-0"><font color="#000000"><strong>^</strong> Mitochondrial DNA sequence heteroplasmy in the Grand Duke of Russia Georgij Romanov establishes the authenticity of the remains of Tsar Nicholas II</font></li>
+     <li id="cite_note-0"><font color="#000000"><strong>^</strong> Mitochondrial DNA sequence heteroplasmy in the Grand Duke of Russia Georgij Romanov establishes the authenticity of the remains of Tsar Nicholas II</font> </li>
 </ol>
 </div>
@@ Line 12: / Line 14: @@
 <h2><span class="mw-headline">See also</span></h2>
 <ul>
-     <li><a title="Homoplasmy" href="/wiki/Homoplasmy"><font color="#0066cc">homoplasmy</font></a></li>
+     <li><font color="#000000">[[homoplasmy]] </font></li>
-     <li><a title="Microheteroplasmy" href="/wiki/Microheteroplasmy"><font color="#0066cc">microheteroplasmy</font></a></li>
+     <li><font color="#000000">[[microheteroplasmy]] </font></li>
-     <li><a title="Paternal mtDNA transmission" href="/wiki/Paternal_mtDNA_transmission"><font color="#0066cc">Paternal mtDNA transmission</font></a></li>
+     <li><font color="#000000">[[Paternal mtDNA transmission]]</font> </li>
 </ul>
-<div id="stub" class="boilerplate metadata">
+<div id="stub" class="boilerplate metadata"></div>