Figuring Out Her Genes
This week we met with a Genetics Counselor at Levine's Testing Center. We really didn't learn anything new though...we just discussed the gene sequencing results from Ambry and what their recommended next steps are.
As I mentioned in a previous post, the gene sequencing panel was able to identify a second mutation on the CFTR gene (Duplication of exon 22). However, the test was not able to tell us whether the mutation was on the same chromosome as the DF508 mutation, or on the opposite one. They would like Joe and I to have blood drawn to determine if one of us carries both mutations, or if we each carry one mutation.
Honestly, I don't really see the point in this testing as I believe we already know the answer based on Sienna's sweat test and pancreatic elastase results. In order for a person to have CF, both genes passed on from the parents would need to carry a CF causing mutation. Otherwise, the healthy gene would allow the CFTR gene to function properly, even if the other gene carried a CF causing mutation. Since Sienna failed her sweat test (twice) and is borderline pancreatic sufficient, the mutations HAVE to be on opposite genes. Otherwise she would only be a carrier and she wouldn't have the elevated sweat chloride levels and moderate pancreatic enzyme levels.
We will likely go ahead with the blood work though, since this will allow us to know who carries which mutation. There is a small chance that the duplication of exon 22 is a spontaneous mutation...which means neither of us actually carry the mutation. This is a slim chance I know, but hey, Sienna is a special one isn't she?
Here's our little peanut at the genetics appointment.
As I mentioned in a previous post, the gene sequencing panel was able to identify a second mutation on the CFTR gene (Duplication of exon 22). However, the test was not able to tell us whether the mutation was on the same chromosome as the DF508 mutation, or on the opposite one. They would like Joe and I to have blood drawn to determine if one of us carries both mutations, or if we each carry one mutation.
Honestly, I don't really see the point in this testing as I believe we already know the answer based on Sienna's sweat test and pancreatic elastase results. In order for a person to have CF, both genes passed on from the parents would need to carry a CF causing mutation. Otherwise, the healthy gene would allow the CFTR gene to function properly, even if the other gene carried a CF causing mutation. Since Sienna failed her sweat test (twice) and is borderline pancreatic sufficient, the mutations HAVE to be on opposite genes. Otherwise she would only be a carrier and she wouldn't have the elevated sweat chloride levels and moderate pancreatic enzyme levels.
We will likely go ahead with the blood work though, since this will allow us to know who carries which mutation. There is a small chance that the duplication of exon 22 is a spontaneous mutation...which means neither of us actually carry the mutation. This is a slim chance I know, but hey, Sienna is a special one isn't she?
Here's our little peanut at the genetics appointment.
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| Waiting for the Geneticist! |
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