HKU team finds gene for intestinal disease
University of Hong Kong researchers have identified a gene linked to a painful, sometimes lethal intestinal disease.
The medical faculty's assistant surgery professor, Vincent Lui Chi-hang, and paediatric surgery chair Paul Tam Kwong-hang presented the discovery yesterday and said it would be vital in genetic-disease research.
They called the disease a 'model' and their findings wide-reaching because, like 95 per cent of genetic illnesses, it was caused by multiple genes.
Dr Lui's team discovered that the homeobox B5 gene affects a gene responsible for bowel nerve-cell development and identified DNA sequences that increased the likelihood of developing the disease.
Without nerve cells, the intestine cannot move food. The condition is called Hirschsprung's disease in patients with no rectal nerve cells and hypoganglionosis in patients with an inadequate amount.
Sufferers vomit, develop inflated and punctured intestines and, if left untreated, sometimes die.
Dr Lui's study, which began in 2003 and lasted four years, involved experiments on mice, human case studies, DNA data and blood samples.
'Hirschsprung's not only has a tremendous psychosocial impact on the patients, but also a heavy financial burden on the health care system,' Professor Tam said.
Hirschsprung's and hypoganglionosis are often hereditary, though they sometimes skip generations without producing symptoms.
The mainland had an average of 1,000 cases per year and Hong Kong had 12, Professor Tam said.
Doctors should diagnose and operate on patients in infancy, Professor Tam said. If a baby does not have its first stool within 24 hours of birth, it signifies a possibility of Hirschsprung's.
Seventy per cent of sufferers exhibit symptoms of the disease from birth.