Miriam Borthwick
15. feb. 2022
A gene found for severe recurrent muscle breakdown disease - rhabdomyolysis
WA geneticist receives national award: Growing up, Mitch Thompson used to suffer leg pains, usually after physical activity but he and his family put them down to growing pains.
“The day after sports days were the worst,” he said.
However, at 14 Mitch was hospitalised for a week. His muscle tissue was breaking down. Doctors feared acute muscle protein in his blood would damage his kidneys.
Then on the first day of university Mitch collapsed.
“It was a really hot day and I had decided to walk from college to uni. After collapsing I was raced to hospital. The incident had brought on compartment syndrome which causes muscles to die. I had six surgeries over a few days. I lost a lot of muscle volume. I was out of it for most of it, but it was really hard on my parents.”
Mitch spent a month in hospital with the life-threatening condition and three months in a rehabilitation centre learning to walk again.
It took a number of years, and an international hunt, to identify the genetic cause of the life-threatening muscle breakdown condition, rhabdomyolysis.
In Perth, Dr Gina Ravenscroft at the Harry Perkins Institute of Medical Research was sent Mitch’s genetic material.
“Mitch had gone through all the usual tests to find a diagnosis, but one hadn’t been found.
“However, our analysis found two copies of the same mutation in one particular gene, the obscurin gene, which means the mutation had been passed on by both parents.
“We knew through colleagues in London that they had a patient with very similar symptoms and also two variants in the same gene. Through the international network of specialists we were contacted by clinician researchers in Finland, Turkey and Pittsburgh in the USA. They had patients with this same disease and mutations in the obscurin gene.
“Pathwest identified another Australian case, in Queensland, through routine diagnostic testing, as the close relationship between the research and diagnostic lab meant that this gene was added onto the PathWest diagnostic panel prior to the publication of this discovery.
“All in all there were six patients around the world. Three were athletes in their youth representing their college or country in their chosen sport, whose muscles had started to breakdown when they did intense physical training particularly on hot days,” Dr Ravenscroft said.
The geneticists were able to find a match with the mutations Dr Ravenscroft had discovered.
For Mitch, the discovery means that possibly one day there could be treatments developed.
“I have to be quite sensible about being in heat and doing too much. The condition is quite limiting in that regard as there’s currently no treatment.”
“The great thing about Dr Ravenscroft discovering the genetic cause of this is that hopefully it will lead to the development of a treatment one day,” he said.
Having a genetic diagnosis can also enable pre-pregnancy screening for a couple planning a family.
Dr Ravenscroft has been awarded the Lorne Genome Mid Career Researcher Award for her research into the genetics of neuromuscular diseases, including rhabdomyolysis. The new discovery of obscurin mutations as a cause of rhabdomyolysis is published online in the prestigious journal Brain.
https://pubmed.ncbi.nlm.nih.gov/34957489/
https://academic.oup.com/brain/advance-article-abstract/doi/10.1093/brain/awab484/6484509
Media assets: Images of Mitch Thompson post-surgery
