Tuesday, April 10, 2012

Honorary Geneticist!

The neurologist at Children's sent me a copy of the genetic analysis findings for Geri-Berry. He told me "This will be Greek to you... it's nearly Greek to me."

Well, he didn't count on me being a former engineer. Part of my job when I worked at the research labs was to review and edit the test reports produced by my (truly delightful and thoroughly competent) Indian coworker. English was not her strong suit. So if I can read mangled technical English written by a very sweet Hindi chemist, I can read anything.

According to the results our little one has a gain of 1.6Mb at the 8p23.1 region. Which means that chromosome number 8 has duplicated material on the upper portion. Another way of putting it is that the 23rd band on the 8th chromosome is thicker than normal. 8p23.1 abnormality is a very rare syndrome, 1 in 65,000 is the generalized incidence, but in the study cases it presents with a certain facial appearance and with some heart defects, fused or webbed fingers or toes, metabolic disorders, and general developmental delay.

It also typically presents with a gain around 3.7Mb.

The facial features tend to be a prominent forehead with high, arched eyebrows. The heart defect tends to be Tetralogy of Fallot (TOF).

Of course we have to wait for the results of the FISH study, but on first wag I have to say that this sounds like a miss to me. Her gain is low for a true 8p23.1 syndrome. Her facial dysmorphism (she does have some) doesn't match up with the described features. She has no metabolic problems. She has two heart defects, both very minor, and none of them considered TOF. A TOF diagnosis is comprised of finding 5 distinct abnormalities all clustered together. She has two abnormalities, but only one of them is a part of TOF. She has no fusing or webbing of her digits at all.

It may be that she has some extremely slight touch of this 8p23.1 syndrome, maybe in the form of developmental delay. She is, clearly, delayed... but is that really due to a genetic problem or is it due to her complete deprivation of stimulation during her early years? Or maybe it's just due to her visual impairment? She's behind, but she's catching up faster than we ever would have hoped or dreamed and appears to be quite intelligent. She's actually very normal, for a blind kid!

The good news is that, even if she does have some level of 8p23.1, the outlook is good. This syndrome doesn't limit lifespan, and it doesn't appear to have a huge effect on quality of life. In the higher gain, typical cases, adult patients were able to live almost entirely independently. And that's the people who presented all of the mentioned symptoms in a severe degree. So for Geri to have such a slight manifestation of the characteristics, and such a low gain in this troublesome region, then I would feel safe in assuming that the overall impact to her ability to live a happy, independent adult life would be even less than typical.

She's got a bit of extra genetic material, but nothing to write home about. So I'm writing about it. :) I'll let you know when we get the FISH results back. Until then, all is going very well on the homefront. I hope it's going well for you, too!

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