<div class="FTQUOTE"><begin quote>So, does this also mean that a person with CF could still possibly have a child with CF, even if their partner is not a carrier?</end quote></div>
Interesting question... I am doing a little research on this right now and so far have come across this in this article:
<a target=_blank class=ftalternatingbarlinklarge href="http://www.merck.com/mmpe/sec22/ch327/ch327e.html">Unusual Aspects of Inheritance</a>
<div class="FTQUOTE"><begin quote><b>Uniparental disomy</b>
Uniparental disomy occurs when both chromosomes have been inherited from only one parent. It is very rare and is thought to involve trisomy rescue; ie, the zygote started off as a trisomy (having 3 instead of 2 of a particular chromosome) and one of the 3 was lost, a process that leads to uniparental disomy when the 2 chromosomes that remain are from the same parent (in about 1 /3 of cases). Uniparental disomy may cause abnormal inheritance patterns. For example, if duplicates of the same chromosome (isodisomy) are present and carry an abnormal allele for an autosomal recessive disorder, affected people can have an autosomal recessive disorder even though only one parent is a carrier.</end quote></div>
If I come across more, I will post it. <img src="i/expressions/face-icon-small-smile.gif" border="0">
eta: According to <a target=_blank class=ftalternatingbarlinklarge href="http://en.wikipedia.org/wiki/Uniparental_disomy">wikipedia's article</a> about Uniparental disomy, the first identified case of this was in 1988 and involved a 'girl w/ CF with unusually short stature and 2 copies of maternal chromosome 7'!
Here is the 'real' article: <a target=_blank class=ftalternatingbarlinklarge href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1715272">Uniparental disomy as a mechanism for human genetic disease</a>; abstract below:
<div class="FTQUOTE"><begin quote>A female with cystic fibrosis and short stature was investigated for molecular or cytogenetic abnormalities that might explain the combined phenotype. Analysis with polymorphic DNA markers indicated that the father did not contribute alleles to the propositus for markers near the CF locus or for centromeric markers on chromosome 7. High-resolution cytogenetic analysis was normal, and the result could not be explained on the basis of nonpaternity or a submicroscopic deletion. All of the data indicate that the propositus inherited two identical copies of maternal sequences for much or all of chromosome 7. The occurrence of uniparental disomy could be explained by models postulating postfertilization error, gamete complementation, monosomic conception with subsequent chromosome gain, or trisomic conception followed by chromosome loss. Uniparental disomy in an individual with a normal chromosome analysis is a novel mechanism for the occurrence of human genetic disease.</end quote></div>
Full text is available to read upon clicking the above link.
Interesting question... I am doing a little research on this right now and so far have come across this in this article:
<a target=_blank class=ftalternatingbarlinklarge href="http://www.merck.com/mmpe/sec22/ch327/ch327e.html">Unusual Aspects of Inheritance</a>
<div class="FTQUOTE"><begin quote><b>Uniparental disomy</b>
Uniparental disomy occurs when both chromosomes have been inherited from only one parent. It is very rare and is thought to involve trisomy rescue; ie, the zygote started off as a trisomy (having 3 instead of 2 of a particular chromosome) and one of the 3 was lost, a process that leads to uniparental disomy when the 2 chromosomes that remain are from the same parent (in about 1 /3 of cases). Uniparental disomy may cause abnormal inheritance patterns. For example, if duplicates of the same chromosome (isodisomy) are present and carry an abnormal allele for an autosomal recessive disorder, affected people can have an autosomal recessive disorder even though only one parent is a carrier.</end quote></div>
If I come across more, I will post it. <img src="i/expressions/face-icon-small-smile.gif" border="0">
eta: According to <a target=_blank class=ftalternatingbarlinklarge href="http://en.wikipedia.org/wiki/Uniparental_disomy">wikipedia's article</a> about Uniparental disomy, the first identified case of this was in 1988 and involved a 'girl w/ CF with unusually short stature and 2 copies of maternal chromosome 7'!
Here is the 'real' article: <a target=_blank class=ftalternatingbarlinklarge href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1715272">Uniparental disomy as a mechanism for human genetic disease</a>; abstract below:
<div class="FTQUOTE"><begin quote>A female with cystic fibrosis and short stature was investigated for molecular or cytogenetic abnormalities that might explain the combined phenotype. Analysis with polymorphic DNA markers indicated that the father did not contribute alleles to the propositus for markers near the CF locus or for centromeric markers on chromosome 7. High-resolution cytogenetic analysis was normal, and the result could not be explained on the basis of nonpaternity or a submicroscopic deletion. All of the data indicate that the propositus inherited two identical copies of maternal sequences for much or all of chromosome 7. The occurrence of uniparental disomy could be explained by models postulating postfertilization error, gamete complementation, monosomic conception with subsequent chromosome gain, or trisomic conception followed by chromosome loss. Uniparental disomy in an individual with a normal chromosome analysis is a novel mechanism for the occurrence of human genetic disease.</end quote></div>
Full text is available to read upon clicking the above link.