More than 400,000 babies are to be screened for debilitating, rare inherited conditions, as part of a pilot which aims to discover if more rare illnesses can be identified and treated early on, the government has announced. 

Currently, every one of the around 700,000 babies bon in the UK every year is tested for one of five  illnesses: - cystic fibrosis, which affects one in 2,500 babies born in England, or around 250 a year; - sickle cell, affecting about one in 2,000 babies born in the UK, or about 350 a year; - phenylketonuria, affecting about 80 babies in the UK annually; - congenital hypothyroidism (CHT), affecting about 180 babies in the UK a year; and - medium-chain actyl-CoA dehydrogenase deficiency (MCADD), which affects about 70 babies born in the UK every year.

The new pilots, taking place in Sheffield, Leeds, Manchester, Birmingham and some areas of London, will test for the additional following rare conditions: - maple syrup urine disease, which affects one in 120,000 newborns annually in the UK ; - homocystinuria, affecting one in 100,000; - glutaric acidaemia type 1, one in 100,000 births; - isovaleric acidaemia, one in 100,000 births; and - long-chain fatty acidaemia, one in 100,000 live births in the UK.

The trial, which will run for one year from July 2012, will be funded by the National Institute of Health Research (NIHR), which is providing £600,000 to researchers based at Sheffield Children's NHS Foundation Trust. The results of the trial will be evaluated after a year and the findings will be considered by the UK National Screening Committee.

The newborn screening campaign has now been running for 10 years, and the new pilot "is a fantastic step forward" for the programme which "shows the NHS at the cutting edge," said Professor Dame Sally Davies, chief medical officer for England.

"The pilot will identify more babies with serious conditions, giving them the chance to live a long, healthy life," she added.

The trial will gather evidence to enable understanding of whether offering tests for these conditions to a whole population is of overall benefit, noted Anne Mackie. director of programmes for the UK National Screening Committee.

"The UK is a world leader in screening policy and this is, in large part, due to our rigorous evidence-based approach which requires not only that any screening test be very accurate, but also that there are treatment options available for anyone diagnosed," said Dr Mackie.