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Jane Harris and Darcy Duggan tell the story of their twin boys, James and Ned. Now 16, they were diagnosed back in 2014 at 8 years of age using a genetic test developed in Australia. They are doing very well, with support from the Children’s Hospital Westmead and the international McArdle’s community.


James & Ned Duggan




McArdle’s (GSD5)


Age 8


Age 16



Above: left to right, twins James and Ned.

Symptoms from a very early age

Soon after the twins started school at age 5, James had an episode of rhabdomyolysis. My husband noticed that James had dark urine and when I checked on him later to see if he was rehydrated I was shocked to see his urine was almost black. I now know this is a sign of rhabdomyolysis. The cause of the rhabdo was mysterious to all their doctors at this point and the boys went on to have many episodes. 

On reflection, I think we missed signs of McArdle’s before the twins were 5 years of age because we had always allowed them to pace themselves. They were very active but there was never much reason to push them. For instance, when we went for a bush walk there was much stopping to look at a leaf or a stick. I imagine this was partly natural distraction and partly them allowing their muscles to have a break. They hated learning to swim as pre-schoolers, so we did not make them keep going, fortunately. Swimming can be very hard on muscles. But at school you are expected to keep up and participate, hence the timing of the first observable rhabdomyolysis a week after school started.

Finding support after diagnosis

When the boys were diagnosed, geneticist Himanshu Goel, who visits Tamworth, referred them to the Children’s Hospital at Westmead (CHW), western Sydney, where they saw Dr Khaustuv Bhattarcharya at the Pediatric Metabolic Clinic. The boys’ previous pediatric neurologist had been stumped by their condition and had not seen a McArdle’s patient before. This is of course typical with such a rare condition. Part of what the McArdle’s community does is organize each other to see the same pool of doctors across the world. This gives doctors a chance to have a group with the same rare disease and develop expertise in treating it. At the time Khaustuv treated another teenage girl with McArdle’s. Since then he has gained more McArdle’s patients and his willingness to grow his expertise has been a big help to the twins.

Information from the patient community

Within a week of diagnosis I had found the AGSD-UK website with its wealth of McArdle’s information, and the McArdle’s Facebook group with its friendly and helpful sharing and support. It was excellent to make contact with a couple of McArdleites not far away, in our part of Australia. Lorraine Baguley told of her experience going on the first walking course for McArdle’s in Wales, and I started to formulate a plan for the twins to attend. But it was to be another 8 years before the plans fell into place. 

Support for managing hospital admissions

The visits to CHW and the team there have been very useful. McArdle’s is complex and they help the twins manage it. A remarkable thing the team do is help manage admissions to our regional hospital to treat rhabdo episodes. We can talk to a specialist in the CHW Metabolic Team any time when we have an emergency. That doctor helps us assess if we need to go to hospital for treatment (the IamGSD website now also has a flowchart to help with this decision). We live on a farm nearly two hours from Tamworth Rural Referral Hospital, so the doctor then calls ahead to advise the Emergency Department what to do as soon as we arrive. McArdle’s is something that emergency staff almost always know next to nothing about. The CHW expertise and their relationship with the rural hospital means the boys get much better treatment, much faster. This is important because rhabdo is life-threatening, and painful.

Many rhabdos for simple things

The boys have had dozens of rhabdo episodes. Managing exertion is almost impossible for a young child and at times it seemed actually impossible for a twin boy. They have had serious rhabdos from wrestling and competing with each other. There was a hospitalization from a paper plane race that got out of hand. There was another from climbing a mountain of wood chips; an irresistible thing for any little kid and it locked their legs up in less than a minute. A merry-go-round ride on a school excursion led to an ambulance transfer to hospital. While Ned was on the ground paralysed from the effects on his body, James was still trying to get on, because “It did look really fun, Mum!”

Scroll through some of our photos. Click to enlarge.

Physiology support and learning to use second-wind

Dr Bhattarcharya, along with Carolyn Broderick’s exercise physiology team, have helped us and the boys understand how to use “second-wind” to manage exertion and avoid these rhabdos. The boys get into second-wind very predictably at about 10 minutes of exercising a group of muscles. They can then exercise fairly normally without muscle damage. This has been a game changer, the boys didn’t have a serious rhabdo episode for a couple of years. Which is a relief because as terrific as the Tamworth Pediatric ward is, the frequent 3-5 day stays took a toll on us all. Then out of the blue on a school trip an adventure course saw them crawling through a narrow pipe on the ground, with other kids pressing them on from behind. They overdid it, ended up with rhabdo, and had to be flown back by the Royal Flying Doctor Service.

Avoiding the psychological impact

Having an ultra-rare disease is not easy for lots of reasons. One aspect of McArdle’s is it looks preposterous to others. People with it are often not believed and are characterized as unfit, lazy or uncooperative. Lots of McArdleites, particularly those diagnosed as adults, have serious mental health effects from these attitudes. Good treatment from WCH has not just helped with the physical aspects of McArdle’s, it has also helped the twins avoid the depression and self-esteem issues associated with being misunderstood. 

Massive benefit from the walking course

In the summer of 2023 we at last managed a trip to the UK and included attending a week-long course in Snowdonia, taking in the Children & Parents event and the main adult course, with the twins now aged 16. That week my husband Darcy and I had a glimpse that McArdle’s can give our children more than it takes. This was profound for us. 

The boys got to be part of a group of 16 McArdleites. They got to be teens and young people together. They got to be with older McArdleites. They got to be cared for by ‘aunties’ and ‘uncles’ who either have McArdles, or love and care for a McArdleite. They got to climb mountains they (and we) would never have attempted. They got to do physical things that were bold and audacious. They got to be with a bunch of McArdleites out the front of the pack at the end of a long day’s walk, with the non-M people trailing tiredly behind. And to do it all without rhabdo!

We and the twins have come a very long way from those scary early days of rhabdo, not knowing what was going on. Through the investigations to the diagnosis. Through learning more and more from the doctors and from the support networks. To now being part of an international community and feeling largely in control of this ultra rare muscle condition.

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