I am frequently asked about SMARD, and the questions are usually along one of two lines: 1. What is it? and 2., How is it different from 'regular' SMA? If you've been wondering, you're in luck! Here you go!
What is SMARD? Spinal Muscular Atrophy with Respiratory Distress (SMARD) is part of the Spinal Muscular Atrophy family of disease. It is a motor neuron disease, meaning there is progressive destruction of cells that control motor function, such as breathing and speaking. Cognitive function is unaffected. Like all motor neuron disease, there is no cure. It is an autosomal recessive disease, meaning in theory both my husband and I carry the mutations that cause SMARD (this is as yet to be determined--we still need to be tested). Testing is done through bloodwork and was, until very recently, unavailable in the United States. Dakin's work was sent to England. Initial testing took 3 months and the final, definitive test was not completed until a YEAR after the blood was submitted, though his is a less usual case--he has two different mutations.
How is it different from SMA? SMARD is caused by mutations on the IGHMBP2 gene, whereas 'regular' SMA is caused by mutations of the SMN gene. SMARD typically (from what I have seen) attacks breathing musculature first, and moves to other muscle sets--we saw this with Dakin--he one day could no longer breathe because his diaphragm no longer worked as it needed to. There was no other sign of muscular weakness until long after his inital 'crash' event. Every living child with SMARD that we know of is trached and ventilated--without the diaphragm these children cannot breathe.
SMARD is little understood and even less known. Since IGHMBP2 is such a 'newly' discovered gene, there is not a lot by way of information about SMARD (and what is available is scary or requires an MD to understand). As far as we are aware, there are only maybe 60 diagnosed cases in the world, and we have only been able to contact 5 other families.
We have a few projects in the works to raise awareness of SMARD. We have been working with FightSMA about a SMARD info page on their website, and we have approached Families of SMA with the same request. We also have a Facebook site, started by another parent, to help raise awareness. There are additional plans in the works...more info to come later!!
So there you go. SMARD 101.