Chromosome link with TS identified

Press, 27 January 1988, Page 17

Chromosome link with TS identified

A team of British medical researchers has discovered a link between tuberous sclerosis (TS) and chromosome 9, writes Don Pennington, of the London Press Service science staff. The disease, which is found throughout the world, is inherited and affects about one in every 15,000 in Britain. A singlegene disorder, it is best known for its combination of neurological and dermatological features. It leads to mental retardation in about 50 per Gent of all patients and can also lead to epileptic attacks, intracerebral tumours and skin disorders. Other organs can also be affected, including the kidneys, heart, lungs and bones.

The discovery followed a study of 14 three-generation families and five two-generation families throughout Britain. “We determined the chromosomal location of the TS gene by means of a linkage study of blood groups, plasma proteins and red cell enzymes,” says Dr John Osborne, a member of the research team at Bath’s Royal United Hospital in south-west England. “Medical history records were studied and clinical examinations were also undertaken.” The disease can be transmitted from parents with no apparent signs of the disease to their children, sometimes with devastating effects. “We discovered that the TS gene is close to the gene in the ABO blood group,” says Dr Osborne. •'The blood groups does not

cause the disease, but the manner in which the blood group is passed from parent to child will be an indication of the way in which the disease is passed on. For example, if a woman who has the disease is pregnant, it will now be possible to test her unborn baby and discover what blood group it has. If the disease is associated with the B group in the family and the baby is also group B, then there is a 90 per cent possibility that the baby will also have TS. It will then be possible to terminate the pregnancy if the parents wish.” To date there are only a few diseases for which the gene location is known and this is the latest example. The next stage will be to investigate other types of markers so that the gene location can be found even closer in an effort to discover a cure for the disease.

The $130,000 research programme was sponsored by the Tuberous Sclerosis Association of Great Britain and the British children’s food manufacturer, Cow and Gate. Research was also undertaken at the Duncan Guthrie Institute of Medical Genetics at Glasgow in Scotland, the South-West Regional Blood Transfusion Centre at Bristol, south-west England, the Medical Research Council (MRC) Biochemical Genetics Unit at University College, London, and the Division of Immunochemical Genetics at the MRC Clinical Research Centre at Harrow, London. y