Is There a Karyotype for Cystic Fibrosis?
Tuesday, August 3rd, 2010 at
8:52 pm
razzldazzl1212 asked:
i’ve researched cystic fibrosis and tay-sachs disease for a biology project. we’re supposed to include a picture of a karyotype, but neither of them have karyotypes that portray the disorder. someone said it’s because the mutation is too small for a karyotype, but is that true for almost all autosomal genetic diseases, other than down’s syndrome?
+ are there karyotypes for hemophilia, william’s syndrome, or leukodystrophy?
thanks!
Tagged with: Cystic Fibrosis • Hemophilia • Karyotypes
Filed under: Cystic Fibrosis
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Cystic fibrosis (CF) is a hereditary disease that affects mainly the lungs and digestive system, causing progressive disability, and, for most, early death. Formerly known as cystic fibrosis of the pancreas, this entity has increasingly been labeled simply cystic fibrosis] Average life expectancy is around 36.8 years, although improvements in treatments mean a baby born today could expect to live longer.
Difficulty breathing and insufficient enzyme production in the pancreas are the most common symptoms. Thick mucus production, as well as a less competent immune system, results in frequent lung infections, which are treated, though not always cured, by oral and intravenous antibiotics and other medications. A multitude of other symptoms, including sinus infections, poor growth, diarrhea, and potential infertility (mostly in males, due to the condition Congenital bilateral absence of the vas deferens) result from the effects of CF on other parts of the body. Often, symptoms of CF appear in infancy and childhood; these include meconium ileus, failure to thrive, and recurrent lung infections.
Cystic fibrosis is one of the most common life-shortening, childhood-onset inherited diseases. In the United States, 1 in 3900 children is born with CF] It is most common among Europeans and Ashkenazi Jews; one in twenty-two people of European descent carry one gene for CF, making it the most common genetic disease among such people.
I would lean towards certain autosomal diseases such as CF having too small a mutation to significantly alter an entire karyotype. For instance, the most common mutation for CF is the delta508 mutation, which alters simply one base pair on the 508th base pair position on the transmembrane regulator gene (this mutation ultimately causes a dysfunction in transmembrane transport and causes the symptoms of CF disease).
I might be confusing your question for something else but if you want just an image of the gene only that is altered, you can probably find one on the web. If I remember right, the chromosome altered is Chromosome 7 and you might want to look for the CFTR gene (cystic fibrosis transmembrane conductance regulator gene).
EDIT: I looked up CFTR gene on Wikipedia and did find an image of the gene.
Unfortunately, I haven’t researched the other diseases you mentioned so I can’t help you there
Other than William’s syndrome, all of the genetic disorders you’ve listed result from a mutation in a single gene, and would not have distinctive karyotypes. William’s is caused by a larger deletion in chromosome 7, but may not be discernible through conventional chromosomal imaging.