GPIBD15 is transmitted in an autosomal recessive manner which means that both copies of the gene must carry the mutations for the disease to occur. There are multiple types of mutations that can occur in the GPAA1 gene. These mutations alter the function of GPAA1. When GPAA1 is mutated, it can no longer help in the formation of GPI-anchored proteins. The GPI-anchored proteins are important for the development and functioning of the brain.