A new process in which the whole human genome is analysed at one time has been developed by scientists in Berlin.
The process was used for the first time on three children in a family who suffer from a rare form of mental retardation (Mabry Syndrome).
The results reveal that the new genome sequencing processes are suitable for tracking down individual mutations in the genome and for the identification of these mutations as the cause of rare diseases.
"It was like the proverbial search for a needle in a haystack. We fished out solely the 22,000 genes from the entire genome, decoded their sequence and examined them for mutations. Using new bioinformatic analyses, we were able to limit the number of mutation candidates to two - one of which is ultimately responsible for Mabry Syndrome," Nature quoted Michal Ruth Schweiger as saying.
The available results will enable, for example, the identification of the genetic risk in affected couples that would like to have children.
Mabry Syndrome is a rare recessive genetic disorder that causes mental retardation, seizures and a characteristic mutation in the blood values of those affected. The raised level of the enzyme alkaline phosphatase, which usually plays a role in bone metabolism, can be measured in the blood.
The researchers succeeded in showing that in the case of Mabry Syndrome the PIGV gene is mutated, in such a way that the alkaline phosphatase is not adequately connected to the cell membrane.
The researchers assume that PIGV in the brain is responsible for the anchoring of many other proteins and that this malfunction is responsible for the mental retardation associated with Mabry Syndrome.
The methods of genome analysis developed here enable the identification of mutations even in the case of extremely rare diseases and represent an important step forward in the direction of individualised molecular medicine.
The study is published in Nature Genetics.