Inherited Metabolic Disorders
“Ellis was just four days old when we got a phone call from the geneticist. She explained to us that Ellis’s test for PKU had come up positive. We make sure to eat as normal as we can. We’re really proud of that, of making sure her food looks like our foods – so that PKU doesn’t define her, she’s so much more than that.
We love to be a part of the PKU community, showing others a success story, how as a family we’re no different, we experience life just the same.”
What are inherited metabolic disorders?
Inherited metabolic disorders (IMDs), also known as Inborn errors of metabolism (IEM) are a group of rare disorders caused by genetic defects that affect the body's ability to break down particular nutrients in food e.g. amino acids. Inherited (most often via both parents) and detected shortly after birth by newborn screening, IMDs are usually caused by defects in enzymes that help break down ('metabolize') food, which results in the production of abnormal protein, which in turn can alter the normal functioning of cells. If not managed, IMDs can cause a wide array of symptoms including delays in physical and mental development1,2.
The role of nutrition in inherited metabolic disorders
For around fifty of the known inherited metabolic disorders, management is through a lifelong commitment to a restricted diet. In the example of the amino acid disorder Phenylketonuria (PKU), individuals cannot break down the amino acid phenylalanine, which leads to a build-up on the brain. A build-up of this kind can cause long-term health issues, including irreversible brain damage.
Since amino acids such as phenylalanine are the building blocks of the protein we eat, PKU patients must stick to a low-protein diet, alongside supplementation of the essential and non-essential amino acids that our bodies need to function properly. For all people with metabolic disorders managed through diet, special foods will help them to meet their nutrition requirements while providing the necessary dietary management of the disorder.