Adult polyglucosan body disease

Adult polyglucosan body disease, often shortened to APBD, is a rare inherited condition of the nervous system. Signs usually first appear between the ages of 35 and 60, beginning with numbness and tingling in the legs from peripheral neuropathy and with progressive muscle weakness and stiffness, so that people walk unsteadily, lose balance and fall more easily. Damage to the nerves that control the bladder, called neurogenic bladder, often appears early and makes it hard to start or stop the flow of urine. Over time most people lose control of the bladder, the bowels and the limbs, and damage to the autonomic nervous system disturbs blood pressure, heart rate, breathing, digestion, temperature regulation and sexual response and brings daily bouts of exhaustion. About half of those affected develop dementia. Mutations in the GBE1 gene, which makes the glycogen branching enzyme, usually cause the disease, and abnormal glycogen called polyglucosan bodies builds up in nerve cells; the inheritance is autosomal recessive. Roughly 200 people had been diagnosed worldwide, and researchers suspect the disorder is underdiagnosed.