M.I.A. (slideshow)

This patient had an adult-onset chronic neurological condition marked by both central and peripheral nervous system dysfunction, and it took nearly a decade to make the correct diagnosis. The diagnosis of adult polyglucosan body disease was made by nerve biopsy, and subsequent results for glycogen branching enzyme activity in leukocytes showed marked reduction, as has been reported for Ashkenazi Jewish patients with adult polyglucosan body disease. This was confirmed by DNA analysis of his glycogen branching enzyme gene showing homozygosity for the Tyr 329 Ser mutation. DNA testing of the glycogen branching enzyme gene was performed on the family, and his brothers who were at that time age 49 and 54 had no issues with walking but did have bladder problems, and they were also found to be homozygous for Tyr 329 Ser while their parents were both carriers. The patient's visual dysfunction was most likely due to nerve infiltration of polyglucosan bodies and cerebral degeneration.