New research on hypochondroplasia and epilepsy

I just came across this research abstract yesterday as I was working on my HCH - GH project.

It is a retrospective, small and quite bias study, in the sense that they didn't do MRIs for all their 13 patients, but used the MRIs from their archives (for 8 kids). Now, of course kids with HCH don't typically get MRIs done, unless they have seizures or accelerating head growth and the authors correctly point this out. Nevertheless their neuroimaging findings are pretty uniform.

If you have 4 USD you can buy read-only access on Deep-dive for 7 days. I think it's money well spent. I am also trying to see if I can get a pdf from the publishing journal through their parent access program, in which case I will be happy to e-mail the file to any parent who will ask me.

It reinforces the points about the kind of seizures that children with HCH have as well as the cognitive/learning disorders and speech issues that Dr Pauli has documented before.

I have also tried to contact the authors to get some clarifications on a few points. See if we get anywhere with that. In addition with the selection bias, I have 2 main questions: it doesn't define what is meant by mild intellectual disability, I will try and get an IQ range and it would be great to see a verbal versus non-verbal results. It would be good to get a range on the speech delay as well.
Secondly, it was done by neurologists; when listing the specialists children attended ENT was not mentioned, I would be quite interested in understanding that aspect as well.

I truly hope that if I get accepted to do my PhD, all of you will participate in my research project, so that we can get a study on the way with larger numbers and get some answers for future parents and our children's generation.

Epilepsy 2

Hypochondroplasia - epilepsy 1 - is the post on my blog which gets the most hits every month hands down. Which tells me 2 things that I already know...

1. It is extremely under-researched, under-published, not even geneticist who deal with skeletal dysplasia patients seem to know a lot of the time based on parental reports.

2. It could be more common than the 8-10% which has been quoted previously. This number was not based on any research, just observations by medical professionals who see kids with HCH.


When we met with the 3 lovely WI/MN families in October whose children have HCH, Fi was the only one who didn't have seizures as an infant. They all had the common mutation...

So if you are reading this and you have questions or comments about this, feel free to e-mail at tiny.hypo at gmail. com

Hypochondroplasia -epilepsy

OK, as promised, I will start adding bits and pieces for the medical section of this blog as part of my new year's resolution.

Please remember that all of this is my opinion and I am not medically trained.

I would welcome all comments and guest posts, so we can gather and share what we know. 

To start off, let me just say that hypochondroplasia and related seizures is a really interesting and very under-researched subject... Apart from a few studies, not much seems to have been done to explore this area.

Apart from a few experts no one really seems to make the connection, I have personally spoken to 2 parents whose kids have had seizures and were told that it wasn't related.

Even if you read the official gene mutation review: http://www.ncbi.nlm.nih.gov/books/NBK1477/, epilepsy is not mentioned. 


I think one of the reasons why the connection is often not made, is that hypochondroplasia is quite rare; the best estimates say it impacts 1:350,000 live births (so 3-4 in 1 million). But  it is also not typically diagnosed until toddler age and in some cases a lot later. At the same time the vast majority of seizure symptoms seem to occur in the first year of life. So by the time HCH is diagnosed, the epilepsy is either under control with medication or even gone. So no wonder, the connection is not made.


If you do a search on google which I am sure you would have all done, if you are reading this,
you will find that the same few cases are cited over and over again, most often the one about one family where 2 of the children had medial temporal lobe dysgenesis and seizures: http://www.ashg.org/genetics/ashg07s/f20570.htm

Temporal lobe dysgenesis seems to feature in all cases that I could find. The reasoning says that because the FGFR3 also expresses in the brain, it could be causing this structural abnormality.

In terms of frequency I have seen 5-10% and 10% quoted by different authors.

Children with hypochondroplasia also have macrocephaly (and I will write about this soon) so that could also increase the risk of developing neurological symptoms, including seizures.

All kids whose parents I have spoken to had the the infancy onset seizure-precipitated apnea that appears to be the most common one based on Dr. Pauli's study as well. 



Here is the google docs link to the wonderful Dr. Pauli's study summary:

https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0B23x_OlN3FTNNzA1MDVmZGMtOTUxNS00OWEyLWFiNGEtNjMxYmM2YjllMGQ2&hl=en_US

So what should you do if you worry that your child has seizures, do exactly what you would do with any other child, except when you meet with the doctors, you may want to print out the study and take it with you.

If your child has apneic episodes or seizure-like events, they should have an EEG and and MRI of the brain, but I think this is standard practice anyhow. 

Should you do anything if your child doesn't have seizures? Our pediatrician was really pushing for an MRI and I refused, I didn't want to have Fi sedated and examined for something that she just has a higher risk for.

There will be no MRI...

Before we had a diagnosis, when there was doubt whether  Fi had achondroplasia or hypo I asked our pead to get a CT scan done, based on Dr. Pauli's instructions. For achon it's important to get a baseline to see the amount of fluid and the foramen magnum. A CT is better than an MRI because although it involves radiation, it is quicker, they can do it without sedation and there is a chart about foramen magnum size, this doesn't exist when the imaging is done using an MRI.

 When we found that that she has hypo, these instructions changed: no need to do a CT unless HC is off the average chart, which isn't the case for now anyhow.

Our pead nevertheless referred us to an MRI last month, needless to say up to today we didn't even get an appointment and I have decided that unless her HC is off the chart there will be no MRI. I will not starve this child for 8 hours and have her put under general anesthesia for something she doesn't need. I think she will have plenty of procedures in her lifetime, so we will hold off this one.

Also, if they find some brain abnormality I would just worry myself to death about what that implies in terms of learning difficulties, cognitive issues, etc. And if they told me that everything is fine, I wouldn't believe completely anyhow, since the same doctors told us that the X-rays were all clear... So I guess it's not even about not wanting to know, it is about not wanting to do something that will tell us nothing for sure...