Metabolic disorders

female doctor Within the Inherited Metabolic Disease (IMD) team, we deal with many different types of conditions ranging from deficiencies in enzymes to the body unable to use certain nutrients. Below are some of these types of conditions:

  • Phenylketonuria (PKU) - an inherited condition caused by a deficiency in the enzyme phenylalanine hydroxylase which can cause learning and physical disabilities if left untreated. This is usually picked up from the newborn screening programme offered to all babies
  • Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) - a condition where the body is unable to fully use fat as an energy supply. Typical symptoms may include being sick, drowsy, developing liver failure and low blood sugar levels. This is usually picked up from the newborn screening programme offered to all babies
  • Maple syrup urine disease (MSUD) - a condition where the body loses the ability to use three of the essential amino acids in protein. Newborns show worrying signs including poor feeding, lethargy and convulsions within the first few days of life. Less severe patients may become unsteady or confused during illnesses. This can now be picked up from the newborn screening programme offered to all babies
  • Glycogen storage disease (GSD) - a group of conditions where the liver and/or muscles can't release glucose properly from stored glycogen. Typical symptoms can include being short compared to other children, low sugar levels unless eating regularly, having a big tummy (enlarged liver), weak muscles and muscle pain
  • Galactosaemia - a rare genetic metabolic disorder affecting the body's ability to metabolise the milk sugar, galactose properly. Patients are on a lactose-free, low-galactose diet
  • Urea cycle defects - genetic disorders caused by a deficiency of one of the enzymes in the urea cycle, responsible for removing ammonia from the bloodstream. Symptoms may include poor growth, irritability, vomiting, seizures and confusion
  • Familial hypercholesterolaemia (FH) - a condition where there are abnormally high levels of cholesterol in the blood. Very often several family members are affected. Symptoms are rare in childhood but they can lead to early heart disease in young adults
  • Congenital disorders of glycosylation (CDG) - a group of rare metabolic diseases caused by defects in how sugar side chains are added to proteins. The defects can result in a wide variety of problems including developmental delay, multisystem disease and physical handicaps.
  • Lysosomal storage disorders (LSD) - enzyme deficiencies in the breakdown of complex molecules. Some symptoms include facial deformities, joint stiffness, difficulty breathing, problems with hearing/vision and delays in intellectual and physical development. Special enzyme treatments are available for some of these conditions
  • Organic acidemias - a group of metabolic disorders which disrupts the normal amino acid metabolism, particularly branched-chain amino acids causing a buildup of acids which are usually not present
  • Mitochondrial disorders - a group of disorders in which the ability of the body to generate energy is impaired. These are sadly usually not treatable and lead to a shortened life expectancy

Many of these disorders are picked up by newborn screening. Find out more about screening for metabolic disorders or view the Newborn a Screening & Biogenetics Handbook