An answer from the Geneticist

We finally heard back from the geneticist concerning the last round of testing on Kendal. This is what we have learned....

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There are several genetic mechanisms that cause Angelman Syndrome:

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1. Deletion (not sure if this is the deletion of chromosome 15 or a deletion of genes on that chromosome)

2. Uniparental Disomy

3. Imprinting Defect

4. Gene Mutation

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We have so far tested for deletion, uniparental disomy, and gene mutation. All these tests have come back normal. The next logical thing to do would be to test for the imprinting defect, however the geneticist explained there are no tests to run currently to determine if this was her cause. She further explained that 10%-15% of Angelman kids have no identifiable molecular abnormalities. Would it be a surprise to anyone if Kendal was in that group?

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The first thing I asked her was if they were sure she even had AS. She was very adamant that Kendal has Angelman's primarily because her methylation test came back abnormal indicating AS. She said that the test alone is so comprehensive that it is used for diagnosis purposes. She also referred back to the many clinical characteristics that Kendal has that are in line with what you see in Angelman Syndrome. She assured me that Kendal was diagnosed correctly even though we cannot get the exact mechanism that caused this.

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The main reason for finding out all this information (as it does not change anything) is to learn about recurrence risks in subsequent children. Because they are unable to put their finger on the exact mechanism, they have advised a 1%-50% recurrence risk.

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It's funny because me and James have not really thought much about the recurrence risk. I think with both of us, it really doesn't matter much. Kendal is such a great daughter that fully enjoys life and interacting with people. She loves so much and she is loved so much. We couldn't ask for anything more.