– The protein SOD1 is usually found in all cells of the body, but the child has almost exclusively symptoms from the motor nervous system and especially from parts of the cerebral cortex. This may mean that the motor nervous system is more sensitive than the other nervous systems and much more sensitive than other organ systems, says professor and consultant Peter M Andersen at Umeå University and Norrland University Hospital and one of the researchers behind the study.
Amyotrophic lateral sclerosis, ALS, is a common term for a group of diseases in which neurons in the brain, brain stem and spinal cord that control the body's skeletal muscles die. In Sweden, 200 people are affected annually by ALS.
Incomplete SOD1 protein
The child, a girl who is now 2 years and 9 months, is the youngest patient in the world with ALS-like symptoms. Researchers in Umea have found the cause of her disease, an incomplete SOD1 protein, one of the most important antioxidants of all living organisms. Since the baby's fetal development, birth and the first six months of life were normal, this may support the theory that there may be other mechanisms that can take care of free radicals as well.
– An alternative explanation is that it is an age issue. Maybe the motor nervous system needs to have a certain level of maturity to be sensitive to damage from a defective SOD1 protein, says Peter M Andersen.
At Umeå University, research into ALS has been ongoing since 1992. The goal is to develop treatment for ALS through new knowledge of the mechanisms behind the disease. In particular, molecular biological and genetic aspects of the disease and mutations in SOD1 and other genes are studied. The hope is that by identifying similarities and differences between different types of ALS and other brain diseases, new knowledge can be used that can be used to develop more effective drugs and eventually to preventative measures.
For many years, collaboration has been ongoing with research groups in, among others, Germany, and a large number of blood samples have been collected and studied at Umeå University. In 2018, researchers in Umeå were contacted by the pediatric clinic at the University Hospital in Eppendorf-Hamburg, which sought to find the cause of the then six-month-old child's illness.
– The case illustrates the importance of international cooperation, says Peter M Andersen. The case also shows that sometimes testing by an individual patient can lead to new knowledge of importance to many.
Phenotype of an infant with homozygous truncation of SOD1, Peter M. Andersen, Ulrika Nordström, Konstantinos Tsiakas, Jessika Johannsen, Alexander E. Volk, Tatjana Bierhals, Per Zetterström, Stefan L. Marklund, Maja Hempel, René Santer. New England Journal of Medicine, 2019
Peter M Andersen, professor and Wallenberg Clinical Scholar, Department of Clinical Science, Umeå University, consultant, neurological clinic, Neuro-, head and neck center Västerbotten, Norrland University Hospital, [email protected] and [email protected]