Wednesday, August 8, 2012

Going Back in Time ~ Genetic Results, Commentaries & a Couple of Pictures!

Came across a 2008 email between myself and two other EB moms in which we were comparing notes on our children's genetic mutation screening results - never in my life did I imagine this "scientific jargon" would make any sense to us! Go figure!

TEST PERFORMED: Type VII collagen gene mutation screen


TEST DESCRIPTION: PCR products were generated spanning all 118 exons of the type VII collagen gene. The PCR products were subjected to heteroduplex analysis using denaturing high performance liquid chromatography (dHPLC, Transgenomic WAVE). Exons showing band shifts were sequenced and the sequenced was compared with a normal sequence and known polymorphisms.

RESULT: Two mutations were identified in the COL7A1 gene of Bianca C. The paternal mutation, designated Q2417X, is a cytosine to thymine transition in exon 94 resulting in a STOP (TAG) codon for a glutamine codon (CAG) at position 7249 of the type VII collagen mRNA. This mutation causes premature termination of the collagen VII peptide and results in a truncated and presumably nonfunctional gene product. 

The maternal mutation, designated R669X, is a cytosine to thymine transition in exon 15 resulting in a STOP (TAG) codon for an arginine codon (CAG) at position 2005 of the type VII collagen mRNA. This mutation causes premature termination of the collagen VII peptide and results in a truncated and presumably nonfunctional gene product.

Back in the day Debra's website had a forum and this was a piece from that thread that I posted about my conversation w/Dr. Ellen Pfendner who is now with GeneDX - this was posted in 2004 when Bianca was only 2 years old - WOW:

...obviously there IS a stop in the genetic makeup for both Robert and myself. In speaking to Dr. Pfendner she could be either mild or severe in the future, nothing stated about in between. Simply because she has seen the "STOP" factor go both ways, she knows of phenotyping cases that she studied personally where some of the cells find ways of clipping out the STOP codons and making a partially functional protein. When this happens the type could be much milder than expected. She says the odds could be Bianca could very well be HS, but that she wouldn't bet any money on it. She went on to mention that there are "other physiological factors which appear to play a role in determining how bad it will be". And lastly, she mentioned "I can't be sure if she will present as an HS EB or something milder".

Amazing how reading this today, almost 10 years later, I can reflect on how far we've come. Our mindset, regarding the results, of "that's just words on a paper and only God knows what's in store for us" is what has pushed us through those dark times. In my previous post I mentioned how Dr. Lane made a comment regarding how in a bad mutation a cell could fall off - well I say for us it falls off and then sticks back on...then rinse and repeat! Ha!


~ Bee at her 2 Years Old Birthday Party ~

~Bee 3 years old during Christmas ~
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