Introduction
Metabolic disorders are rare, hereditary conditions that disrupt the body’s metabolism — the process by which nutrients from food are converted into energy and essential building blocks for growth and repair.
In people with a metabolic disorder, this conversion process is impaired. This can lead to the harmful build-up of certain substances or a deficiency of others. The resulting symptoms vary depending on the specific type of metabolic disorder.
On this page:
What examination is carried out to make the diagnosis?
What are symptoms of metabolic disorders?
What is the (dietary) treatment for metabolic disorders?
What financial help will you receive?
What are metabolic disorders?
A metabolic disorder is a genetic condition in which the body cannot properly process certain nutrients. This happens because a specific enzyme is either missing or not working correctly. As a result, substances such as amino acids cannot be broken down efficiently, leading to a metabolic imbalance.
This imbalance can cause a harmful accumulation or deficiency of key compounds, resulting in symptoms that range from mild to life-threatening.
Most metabolic disorders are managed with a lifelong, specialised low protein diet, where protein-restricted foods are supplemented with an amino acid formula or protein substitute. When dietary guidance is followed carefully, children can grow and develop normally.
What is metabolism?
Metabolism refers to all the chemical processes within our cells that convert nutrients from food into energy and the building materials our bodies need to function, grow, and repair themselves.
What are enzymes?
Enzymes are specialised proteins that act as catalysts, allowing the body’s chemical reactions to occur efficiently. Each enzyme has a specific role in processing nutrients. When one enzyme is missing or not working properly, a metabolic disorder can occur.
What are amino acids?
Proteins are made up of smaller building blocks called amino acids. Before our bodies can use protein from food, it must first be broken down into these individual amino acids.
Humans require about twenty different amino acids. Some can be produced by the body, while others — called essential amino acids — must come from the diet. Examples include lysine, tryptophan, phenylalanine, leucine, isoleucine, threonine, methionine, and valine.
How are these disorders diagnosed?
Most congenital metabolic disorders are detected through newborn screening, usually performed shortly after birth. Early detection allows treatment to begin quickly, which is crucial for preventing serious health problems.
What are symptoms of metabolic disorders?
If a metabolic disorder is not treated promptly, symptoms can develop within the first few months of life. Although symptoms differ depending on the condition, common signs include:
- Neurological problems;
- Muscle weakness;
- Liver and kidney problems;
- Poor growth or developmental delay
In severe cases, lack of treatment can lead to coma or death, which is why early diagnosis and treatment are so important.
What is the dietary treatment for metabolic disorders?
If newborn screening results indicate a metabolic disorder, you will be contacted by your paediatrician or GP, who will refer you to a specialist metabolic centre. It is important to attend this appointment as soon as possible to begin dietary management. Treatment usually involves a protein-restricted diet, which is the most effective and long-established approach for many metabolic conditions.
A dietitian specialising in metabolic disorders will develop a personalised dietary plan based on the individual’s medical needs, age, and preferences.
For infants, treatment begins with a special infant formula designed for their specific metabolic condition, often alongside breastfeeding or standard infant formula. As children grow, the diet expands to include low protein solid foods and their prescribed amino acid protein substitute.
The composition of this protein substitute and the exact dietary requirements must always be calculated individually by a specialist metabolic dietitian to ensure safe and balanced nutrition.
