Shedding light on inherited metabolic disorders

Summer 2014

Health issues can be easy to recognize when they appear on the surface or in scans. From coughs and cuts to cancer, the pain and the changes we can see and feel make diagnosis and treatment easier. But what if there is no outer marker, no pain and no obvious health threat to be found? For those who have an inherited metabolic disorder, signs that something is wrong may be hard to spot - or not there at all.

Two-year-old Adam Willison appeared to be a happy and healthy toddler. When he came down with the flu, his parents treated him as you would any two-year-old, with love and rest and fluids. There was no way for the Willison's to know that Adam had an undiagnosed inherited metabolic disorder called medium chain acyl-CoA dehydrogenase deficiency, or MCADD for short.

Normally, the body can draw on its own natural fat stores for energy in times of need - such as in periods of illness, when one's appetite wanes and it is difficult to keep food down. However, those with MCADD cannot reach easily into these fat stores because one of the genes responsible for making the energy-unlocking enzymes is not working properly- if at all. This means that if an individual with MCADD does not eat for an extended period of time, their body will run out of fuel and shut down.

Adam's condition spiraled out of control so quickly, there was nothing is parents could do except wake to their worst nightmare. On the morning of Jan 22, 1990, they found him lifeless in his crib.

After Adam passed away, a physician advised the family that he suspected that MCADD could have been responsible and suggested that a genetic test be performed. The family agreed, and Adam's test came back positive.

Immediately afterwards, Adam's younger sister, April, who was one year old at the time, was tested and it was discovered that she also had MCADD.

"My brother saved my life," says April. "You would never be able to tell that I have MCADD just by looking at me. By being tested so early in life, I have had the opportunity to take proper precautions and lead a healthy life."

According to Dr. Chitra Prasad, a geneticist at LHSC's Inherited Metabolic Disorders Clinic, genetic disorders may be individually rare but they are collectively quiet common in the population. "A simple test can save lives. With genetics testing we can arrive at a definite diagnosis very quickly," she says. "And while not every genetic condition is treatable, many disorders can benefit from targeted therapy. In fact, through proper diagnosis and treatment, individuals with genetic metabolic disorders can live full and healthy lives."

Thankfully, advances in technology and growth in awareness of genetic disorders are making it possible for more lives to be saved every day.

"Our overall knowledge of genetic diseases is expanding tremendously," says LHSC's Dr. Tony Rupar, section head of the Biochemical Genetics Laboratory, Pathology and Laboratory Medicine. "We first became aware of MCADD as a disease in the middle to late 1980's. Previously, the technology wasn't there to identify it and babies that passed away from the disorder were classified as sudden infant death syndrome (SIDS)."

"Thankfully, in 2006, a new technology called tandem mass spectrometry made testing possible for all babies born in Ontario. Now, all newborns are screened for 29 different diseases, most of which have a genetic basis, including MCADD."

To ensure that April stays healthy, she takes carnitine, a supplement that helps her body break down fatty acids, three times each day. She also undergoes regular check-ups with her family physician, a dietician and Dr. Prasad at LHSC's Inherited Metabolic Disorders Clinic. Thanks to her diagnosis, she knows that should she get ill, there are special precautions to take.

"If I am sick, then I go to the hospital right away," she says. "An IV infusion of sugar helps keep my systems running."

Growing up with MCADD wasn't without its challenges. As the extent of April's disorder wasn't fully understood at the time, she had special precautions with her diet and overall health while growing up. She recalls not being able to enjoy the same snacks and treats as her peers, and when she moved out on her own to attend school, she found it challenging to maintain a balanced lifestyle.

"I did well in school, but we went out to eat all of the time. I gained weight, as you typically do in college. But eventually, I had an 'ah-ha moment' in relation to my health and I realized that I had to start taking better care of myself," she says.

Today it's easy to see that April is not only surviving, but thriving. At 25 years old, the accomplished young woman enjoys challenging the limits of her physical fitness and works two jobs as a dietary aide. At the same time as she is pursuing further studies in nutrition and food management to push her career to the next level, she's also training to perfect her 5-km race. Last year, she was the first female through the finish line at the Ronald McDonald House 'Run for the House' race, with a time of 20 minutes, 28 seconds.

"My goal is to complete five kilometers in 18 minutes by the end of the 2014 race season," she says.

April points out that her interest in physical fitness must be carefully balanced with special precautions she must take due to MCADD. As exercise causes the body to burn through energy quickly, she must be vigilant about her caloric intake and be ready to provide her body with nutrition on the go.

Despite her busy schedule, she also takes time to speak at LHSC's annual Metabolic Family Workshop about life with MCADD. Next year, she will be leading a youth group for those with metabolic disorders and sharing her experiences with peer pressure. April has also participated in teaching of fourth-year medical students.

While life with MCADD may be seen as a challenge by some, for April, it is motivational.

"If anything, having a disorder makes you want to achieve more so you can say that 'I can do it and I will,'" she says. "I can ride my bike from Grand Bend to London and back, I can run a half marathon and I can speak about my life in front of 150 people. Because you have a metabolic disorder, it doesn't mean you can't achieve your goals. You just might have to do it in a different way. If you want to do something, do it. Just make sure you're doing it right."

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Adam Willison appeared to be a healthy toddler who loved Bert and Ernie and beets. He had no symptoms of MCADD for the first two years of his life.
Adam Willison (right) with his sister April (left)
Today April Willison has the tools and resources to make the most out of life - a reality that wouldn't be possible without genetic testing and the support of LHSC's Inherited Metabolic Disorders Clinic
April's 2014 goal is to run 5k in 18 minutes