Discovering your baby has an incurable inherited disorder can have a lifelong psychological, social and economic impact on families. But new insights into the molecular genetic bases of two such disorders – Hirschsprung disease and dwarfism – hold promise for developing therapies to lessen the impact. Moreover, the findings may have implications for understanding common disorders that affect millions of people globally. BRINGING HOPE FOR CONGENITAL DISORDERS Hirschsprung disease is a congenital affliction in which babies are born with a bowel that lacks nerve cells to control movement along the gut. The only option for treatment is to surgically remove the affected part of the bowel. But about one-third to one-half of these babies will then suffer lifelong residual problems such as enterocolitis (a potentially life-threatening infection of the bowel), chronic constipation, incontinence and, for a small number, the inability to absorb nutrients. Professor Paul Tam Kwong-hang, Li Shu-Pui Professor in Surgery and Chair Professor of Paediatric Surgery, is a world-leading expert on the disease and has received multiple honours for his work, most recently becoming the first Asian recipient of the Rehbein Medal from the European Paediatric Surgeons’ Association. He has studied treatments can be developed. Professor Tam and his colleagues have focussed on genetic studies and stem cell investigations to find answers. Alzheimer’s link Over the past decade, they conducted the first whole-genome genetic screening of Hirschsprung disease and identified a single gene that can cause the disease in 10 per cent of cases. They also unravelled some of the genetic complexities involved in the other 90 per cent of cases. “We have come to realise that it’s not just one gene but a constellation of changes in different genes that can cause this disease, and that the disease will be different in different patients,” said Dr Maria Mercedes Garcia-Barcelo, Associate the disease for more than three decades, motivated by the impact of the disease itself as well as by its prevalence in Asian populations, where it affects one in 3,000 births against the global average of one in 5,000 births. “The problem with Hirschsprung disease and its treatment is that it can affect patients’ future social behaviour, their educational accomplishments and other activities throughout their lives,” he said. “We overlooked these hidden disabilities in the past and the parents were usually just very grateful that we saved the life of their baby. But if you dig deeper, you can see they need more help. Their child’s long-term survival has come at some cost.” In order to improve that situation, better understanding of the disease is needed so better Team members for the research include (back row from left) Dr Li Peng, Dr Elly Ngan, Dr Clara Tang, (front row from left) Professor Paul Tam and Dr Maria Mercedes Garcia-Barcelo. We overlooked these hidden disabilities in the past and the parents were usually just very grateful that we saved the life of their baby. But if you dig deeper, you can see they need more help. Their child’s long-term survival has come at some cost. Professor Paul Tam Kwong-hang 11 | 12 The University of Hong Kong Bulletin | May 2019 Cover Story
RkJQdWJsaXNoZXIy ODI4MTQ=