“The enzyme deficiency can be mild enough so that the person is able to detoxify ammonia adequately — until there’s a trigger,” said Cynthia Le Mons, executive director of the foundation. The trigger could be a viral illness, stress, or a high-protein diet, she added.
“There was just no way of knowing she had it because they don’t routinely test for it,” said Michelle White, mother of Hefford and a resident of Perth. “She started to feel unwell and she collapsed.”
White blames protein shakes for her daughter’s death.
Since 2014, Hefford, who worked at Princess Margaret Hospital for Children and studied paramedicine, had been competing as a bodybuilder.
It was only after Hefford’s death that White discovered containers of protein supplements in her daughter’s kitchen, along with a strict food plan. White understood then that her daughter, who had been preparing for another bodybuilding competition, had also been consuming an unbalanced diet.
“There’s medical advice on the back of all the supplements to seek out a doctor, but how many young people actually do?” said White.
Le Mons said, “typically, there are nuanced symptoms that just go unrecognized” with mild cases of urea cycle disorder. Symptoms include episodes of a lack of concentration, being very tired and vomiting.
“Sometimes people think it’s the flu and might even go to the ER thinking they have a really bad flu,” said Le Mons, who added that a simple serum ammonia level test, which can detect the condition, is not routinely done in ERs.
It’s unclear whether Hefford suffered symptoms of her condition. White said she hopes her daughter’s story will serve as a warning to help save lives. White believes protein supplements need more regulation. The Australian Medical Association says there’s no real health benefit to such supplements. And, while they may not be necessary for most people, they’re not dangerous to most either.
The estimated incidence of urea cycle disorders is 1 in 8,500 births. Since many cases remain undiagnosed, the exact incidence is unknown and believed to be underestimated.
“There’s a myth that this disorder only affects children,” said Le Mons, who noted one patient reached age 85 before diagnosis.
Regarding Hefford, Le Mons said that “this is not the first time this has happened.” Other athletes, who like Hefford were unaware of their condition, have died when consuming a high protein diet triggered their condition.