What is an Inherited Metabolic Disorder?

The term inherited metabolic disorder refers to a class of medical conditions known as genetic diseases that negatively impact a person’s metabolism with most being defects in single genes. This results in an accumulation of specific substances which are known to be toxic, or which interfere with ordinary function, or which reduce the ability to synthesize vital compounds.

With this said, there are literally hundreds of Inherited Metabolic Disorders with them being extremely complex and therefore hard to describe. To find out more about inherited metabolic disorders, please read on.

Why Is Newborn Screening So Important?

Babies are screened in the UK that is done through a “heel prick test”. This is also often referred to as a Guthrie or blood spot test. The test is carried out when a baby is 5 days old by a midwife who visits the family home. It is the midwife who takes the blood sample which is done by making a tiny prick on a baby’s heel. The blood test is sent to a laboratory to be analysed for nine rare disorders of which 6 are the Inherited Metabolic Disorders as listed below:

  • Phenylketonuria (PKU)
  • Medium-Chain Acyl-CoA Dehydrogenase Deficiency (MCADD)
  • Maple Syrup Urine Disease (MSUD)
  • Isovaleric Acidaemia (IVA)
  • Glutaric Aciduria Type 1 (GA1)
  • Homocystinuria (HCU)

When the “heel test” is carried out and subsequently analysed, there are 3 potential outcomes which are detailed below:

  • Normal – a letter confirming that a baby’s test has come back clear is sent out to parents several weeks after a test has been carried out with a vast number of babies being tested “clear”
  • Insufficient – occasional another test has to be carried out for a laboratory to perform tests again which could be due to a variety of reasons but usually there is nothing wrong
  • Abnormal – tests may come back with the results showing “abnormal” but this is rare. However, should this be the case, the baby who has been tested could have 1 of the 9 disorders that are tested for. Should this be the case, parents are contacted by a specialist so that a second test can be carried out at a regional centre with an end goal being to confirm the first test result. Should the second test that is carried out establishes that a baby has a suspected disorder, parents are given vital advice on what the next steps would be which would include management and treatment

UK Statistics For Babies With an Inherited Metabolic Disorder

Around 1 in 10,000 babies born in the UK have the following disorders:

  • Phenylketonuria (PKU)
  • Medium-Chain Acyl-CoA Dehydrogenase Deficiency (MCADD)

However, the other disorders are much rarer and only occur in 1 in 83,000 to 100,000 new-borns with around 176 babies receiving a diagnosis that is positive through the “Newborn Screening Programme”.

What Would Happen If a Baby Diagnosed With a Inherited Metabolic Disorder is Not Treated?

If a baby is not treated when they are diagnosed as suffering from an Inherited Metabolic Disorder, they would  fall seriously ill which would happen very suddenly. Having been screened and the results coming back “abnormal”, allows for a baby to be treated as a matter or urgency and their dietary needs put into place straight away. This improves a baby’s prognosis and prevents any other serious development issues from occurring. It also prevents any life-threatening symptoms developing which could prove fatal.

When a baby is diagnosed as suffering from an Inherited Metabolic Disorder, they would be cared for by a Specialist Consultant and would also receive support from healthcare professionals who work in a regional centre.

Why Is It That Babies are Screened for so Few Metabolic Disorders?

The National Screening Committee together with Public Health England, have set the standards and criteria for screening in the UK. This covers the following:

  • That an acceptable treatment is in place for patients diagnosed with the disease
  • That facilities where diagnosis and treatment can be carried out are available
  • That there is a recognised “latent” or “early” diagnosis stage
  • That a suitable examination and/or test is available that has few “false positives” as well as “few false negatives”
  • That the examination or test is acceptable to people
  • That the cost which includes diagnosis and treatment is “economically balanced” in relation to the cost of medical care

Advice for Parents and Carers of Children Living with an Inherited Metabolic Disorder

If you care for a child with an Inherited Metabolic Disorder, you can find support and advice at Metabolic Support UK who provide a tailored programme for youngsters between the ages of 12 to 18 known as NextGen. The programme is set up to help young people manage both their condition and the treatment they receive. It also provides youngsters with an Inherited Metabolic Disorder the chance to be included in an supportive and informative community.

What Benefits Could I Claim if I Care For Someone With an Inherited Metabolic Disorder?

If you care for someone with an Inherited Metabolic Disorder, you would have to manage a life-long condition which means that you would have to cope with a wide number of symptoms as well as special needs. You could be entitled to claim benefits which would provide essential financial support when you need it the most. However, knowing if you would be eligible can be confusing and challenging.

You may think that an Inherited Metabolic Disorder is not classed as a “disability” which is a term used when describing “benefits”. However, patients and carers could qualify for financial assistance when living with an Inherited Metabolic Disorder which could include the following:

  • Tax Credits
  • Disability Living Allowance – DLA
  • Carer’s Allowance
  • Income Support
  • Child Tax Credit
  • Housing Benefit

When you make an application for any benefits, it is recommended that you have a diary ready detailing a typical week. This should provide a detailed breakdown of the care your child needs. You should also ask the consultant to provide a supporting letter that would accompany your application to receive any benefits you could be entitled to receive if you care for a child with an Inherited Metabolic Disorder.

Informative Links

If you would like more information regarding  the Newborn Screening Programme, please follow the link provided below:

More information about the Newborn Screening Programme

If you care for a a child with an Inherited Metabolic Disorder and would like help and support, please follow the link below which takes you to the Metabolic Support UK website:

Help and support for carers of children with an Inherited Metabolic Disorder