Newborn babies across England will be screened for more debilitating genetic diseases from Monday.
Cystic fibrosis and sickle cell disease are already picked up in the heel-prick blood test. Four rarer conditions will now also be tested for.
Public Health England expects 30 cases will be identified each year, allowing life-saving treatment.
Wales will follow suit later this month, while Scotland and Northern Ireland have yet to make a decision.
Babies currently have the heel-prick test at between five and eight days old to check for:
- Phenylketonuria (PKU),
- Congenital hypothyroidism (CHT),
- Sickle cell disease
- Cystic fibrosis
- Medium-chain acyl-CoA dehydrogenase deficiency (MCADD).
The baby's heel is pricked and drops of blood are collected and analysed, so babies can get the treatment and support they need from the earliest stage possible.
The extra conditions which will now also be tested for are:
- Maple syrup urine disease
- Glutaric acidaemia type 1
- Isovaleric acidaemia
They are all inherited conditions where babies have problems breaking down amino acids, the "building blocks" of proteins.
For example, maple syrup urine disease is caused by a build up of three amino acids: leucine, isoleucine and valine.
Too much protein in the diet can lead to coma and permanent brain damage. However, early detection means a low protein diet and food supplements can reduce the impact of the disease.
A year-long pilot programme of expanded screening, run by Sheffield Children's NHS Foundation Trust, found 20 confirmed cases of the four extra conditions, in 700,000 babies.
Dr Anne Mackie, director of programmes for the NHS Screening Programmes, said: "Screening for these rare disorders has the potential to benefit around 30 children in England each year.
"The early identification of these conditions can prevent death and significantly improve the quality of life for those living with these conditions."
Wales has committed to starting screening on 12 January.
Public health minister for England Jane Ellison added: "This is really welcome news.
"Expanding the screening has the potential to make a huge difference to the lives of babies born with rare genetic disorders.
"Detecting the disorders early can help prevent babies being severely disabled or even dying, which is absolutely vital for the families affected."
Poppy Bell-Minogue was nine months old when she became unwell.
Unbeknown to her parents, she had maple syrup urine disease, which had led to a harmful build-up of amino acids in the blood and was affecting her brain.
For Poppy's mum, Samantha, and her husband, an early diagnosis of the disease would have made a huge difference.
Instead, they had to undergo several months of tests and brain scans before doctors diagnosed the rare disorder.
In the meantime, Poppy's parents were told they would probably lose her.
Samantha says Poppy's diet from birth would have been different, if they had known: "We wouldn't have given her breast milk, formula milk or food high in proteins after she was weaned."
Eating these foods made her condition worse and led to high levels of harmful amino acids in her body which may have damaged her brain.
Source: BBC News (http://www.bbc.com/news/health-30657478)