Potential new treatment for rare, inherited metabolic disease

The rare disorder alpha-mannosidosis can cause serious damage to the nervous system and other organ systems. In Tromsø, Norway, researchers have been studying the disease for 20 years - and a treatment may soon be available.

Alpha-mannosidosis is a rare, inherited metabolic disease causing mental retardation, serious skeletal and muscular abnormalities, and recurrent infections. It affects roughly one in 500 000 people.

The new treatment is based on supplementing alpha-mannosidase, the enzyme which is deficient or does not function properly in people born with the disorder, explains Professor Øivind Nilssen of the Department of Medical Genetics under the Institute of Clinical Medicine at the University of Tromsø.

International efforts

The researchers in Tromsø were the first to characterise the alpha-mannosidosis gene, and have also supplied the alpha-mannosidase enzyme for therapy trials on animals.

Now Professor Nilssen's group is participating in its third EU project on this topic. If all goes well, clinical trials being held on patients in Denmark could lead to a treatment for the disease in four to five years.

At least 100 different mutations

The researchers in Tromsø have provided an important basis for developing the medication being tested. Collecting and analysing genetic materials from patients throughout Europe, the group has identified more than 100 different pathogenic mutations in over 170 families.

"Through our participation in the EU projects, we have continued working with these materials," says Professor Nilssen. "For example, we have created a database of mutations which contains clinical, demographic, genetic and biochemical data. Information about the patients taking part in the clinical trials is entered as well. By analysing this data we can predict how they will react to the treatment."

Treating the physical and mental symptoms

"We believe the treatment will improve the children's mental development, while in older patients the primary aim is to alleviate the suffering associated with bone disease and immune deficiency," concludes Professor Nilssen.