Brussels, 17 May 2004
A team of European and North American scientists has discovered the gene for Cornelia de Lange syndrome (CdLS), a disabling genetic disease that affects one in 10,000 children. It is hoped the findings will lead to a genetic test for a quick and accurate diagnosis of the syndrome, as well as prenatal testing.
First discovered in 1933, CdLS can cause impaired development, mental retardation, missing fingers or hands and heart defects. In the past, CdLS tended to be fatal in infancy, but children affected with the condition now live to adulthood.
The international team analysed the genomes of 12 families with more than one member suffering from the disease. The innovative approach the scientists used in pinpointing the gene may lead to research in other genetic conditions, above all 'orphan diseases'.
The researchers identified a large gene, NIPBL, on chromosome 5. Mutations leading to CdLS take place at different locations within that gene. The scientists then combined this discovery with cytogenetic information, ie: the details of chromosomal rearrangements in a patient with CdLS.
'This discovery is exciting for a number of reasons,' said Julie Mairano from the Cornelia de Lange Syndrome Foundation. 'It will pave the way for genetic tests to confirm a diagnosis and comfort patients who already have child with the syndrome. It will raise awareness of the disease among physicians and scientists, and most importantly, focus interest on better treatments for children with Cornelia de Lange Syndrome.'
The disease had been a mystery for scientists for decades. Dr Ian Krantz, one of the lead researchers from the children's hospital of Philadelphia explained that 'this syndrome has been confusing for a long time, because it's been difficult to trace one source for its multiple effects on many organs.'
Professor Tom Strachan from the Institute of Human Genetics at the International Centre for Life in Newcastle in the UK told the BBC that 'when you see a genetic condition you can normally study it in families and see how it moves from one affected individual to another.' In the case of CdLS, however, the disease is so debilitating that parents often only have one child and few individuals with CdLS go on to have children of their own. It is therefore rare to find parents and children who both have the disease he explained.
'Fortunately,' added Dr Krantz 'the disease has a low recurrence risk. Families having one child affected by CdLS have only a one per cent chance that a subsequent child will be affected. When a prenatal test is developed we will determine before birth whether the foetus is among that one per cent.'