Researchers have managed to identify and describe a rare new brain disease, which is characterized by reduced brain growth in affected children and can eventually lead to paralysis of the legs. The previously unknown neurodegenerative condition was identified in two separate families living more than 1,600 kilometers (1,000 miles) apart, and shows a strong genetic component as multiple siblings in each family are affected.
After five years of studying the two families and the 14 children who have the condition, the scientists were able to pinpoint exactly which mutated gene was responsible for the neurological disorder, narrowing it down to GPT2. The condition affects brain development in children, who show intellectual disability and a degeneration in motor skills. For example, up until the age of three, the children will typically be able to walk normally, but then they will steadily lose function of their legs as a condition known as spastic paraplegia develops.
While the gene GPT2 is expressed in the nucleus of the cell, the enzyme it codes for actually gets to work in the mitochondria – the powerhouse of the cell. The result is that the enzyme cannot function correctly, leaving the developing brains of young children without the biosynthetic abilities they need to grow properly. It may also lead to reduced levels of other substances necessary in preventing neurological degeneration.