Leuven, Belgium − 2 to 3 children in 100 are born with a mental handicap. This can be caused by a genetic defect, but in 80% of the cases scientists do not know which genes are responsible. Now, VIB researchers connected to the Katholieke Universiteit Leuven, in collaboration with an Australian research team, have discovered that, in a portion of these patients, the mental retardation is caused by a twofold production of two proteins (HSD17B10 and HUWE1). This is the first time that scientists have found that duplication of a protein leads to mental retardation. The discovery offers promising possibilities in the search for remedies, because its easier to reduce an over-production of a protein than to repair a defective protein or to replace a missing protein.
Defects on the X-chromosome
Mental retardation occurs in 2 - 3% of our population. This can be attributed to external factors (such as a shortage of oxygen at birth) or to defects in the DNA. When the cause is genetic (hereditary), identifying the precise defect is crucial for the patients medical support or for assessing the risk of having children. Scientists estimate that, in about 30% of the patients, a defect on the X-chromosome is the underlying cause. This is called X-linked mental retardation (XLMR). In over half of the XLMR patients, the gene responsible has not yet been identified.
2 proteins in the leading role
Guy Froyen and his colleagues in the Human Genome Laboratory (VIB K.U. Leuven) teamed up with Jozef Gczs research group (University of Adelaide, Australia) to look for new genes that might lie at the basis of XLMR. With the aid of a very specialized molecular technology (X-chromosome specific array CGH), they studied the genes of some 300 XLMR families. In 6 of the families, they discovered that a certain part of the X-chromosome had been duplicated. Because of this duplication, two proteins, HSD17B10 and HUWE1, were produced in too high a
|Contact: Sooike Stoops|
VIB (the Flanders Institute for Biotechnology)