Touching Lives - September 2014
How screening saves children from lifelong learning disability
For adults, the hormone thyroxine is important in maintaining energy levels to allow everyday activity. But in children, and especially in babies, it has another vital function: it is essential for the normal growth and development of the brain and body. At around six weeks after conception, a baby’s thyroid gland moves from the back of the tongue down the neck to its usual position just below the Adam’s apple. In babies with congenital hypothydroidism (CHT) this gland may not be fully developed, it may not have developed at all, or it may not have moved to the correct position. Problems with the production of the hormone thyroxine, or very low levels of thyroid stimulating hormone, can also cause CHT.
If left untreated, the condition can cause lifelong physical, developmental and learning disabilities, including severe learning disability and difficulty with walking, talking and feeding. For some children, this means they may require lifelong care.Yet the condition can easily be treated with a synthetic form of thyroxine in liquid form, suitable for tiny babies, or in tablets.
In 1978, Action funded a one-year pilot study led by the late Professor Barbara Clayton at Great Ormond Street Hospital, to screen for CHT in babies in the north east and north west Thames regions. Professor Clayton was already responsible for ‘heel prick’ testing (now known as ‘newborn screening’) for the condition phenylketonuria (PKU) in this region, and proposed that CHT screening could be linked to this. During the pilot, more than 87,000 babies were screened and 26 were diagnosed with CHT – around twice as many as estimated at the start of the study. Researchers found that more than 92 per cent of babies diagnosed with CHT through the early heel prick test were identified before their symptoms became apparent. The research, which was extended following funding from the Medical Research Council, showed that early diagnosis and treatment helps save the vast majority of babies with CHT from lifelong learning disability. In the early 1980s routine CHT screening of all newborn babies was introduced throughout the UK.
For Nicky and Simon, whose daughter Emma was diagnosed with CHT as a newborn baby, the research funded by Action has made an enormous difference. “We are so grateful for the research which has been done to reach this point, where this rare condition can be picked up at an early enough stage to prevent as much as possible any negative impact on new lives,” says Nicky. Emma’s arrival was problem-free, as Nicky explains: “By the time Emma was born I was already 40 and so we were delighted when she arrived with 10 fingers, 10 toes, and everything appearing to be in the right place. There were no complications with the pregnancy or birth and no signs that Emma had congenital hypothyroidism.”
But when Emma was just nine days old, Nicky received a call from Lewisham Hospital Paediatric Team asking to see her daughter as a matter of urgency. “I cannot remember much about the actual call itself, other than that a doctor was telling me that my newborn daughter, most precious and tiny, was fundamentally unwell in some way,” says Nicky.
CHT screening had identified a problem which indicated that Emma’s body was attempting to ‘kick start’ the function of her thyroid gland.A scan showed that Emma’s thyroid gland was not in the usual position. Doctors prescribed thyroxine, which Emma now takes daily as part of the family’s breakfast routine.
“Had the heel prick test not been done, then I am unsure how long it would have been before the condition was picked up on, by which point Emma’s mental and physical
development could well have been compromised,” Nicky reflects. “We don’t know if there will be any further challenges ahead for Emma due to her condition, but her current physical growth and mental development appears to be unimpaired. She is such a cheeky monkey with a smile that would melt the coldest heart. She blows our socks off every day and we could not be more proud of her and her brother!”