People born with this rare, inherited condition have poor muscle coordination, some degree of mental retardation, uncontrollable head and eye movements and difficulty speaking or walking.

Now, in a discovery that reinforces the importance of the mouse to human genetics, scientists at the University of Michigan Medical School have discovered two mutations in a gene called ATCAY, which appear to be responsible for Cayman ataxia in humans and for similar neurological disorders in mice.

Cayman ataxia is one of about 100 rare inherited neurological disorders with symptoms that include ataxia, according to Margit Burmeister, Ph.D., a senior associate research scientist at the U-M Mental Health Research Institute and an associate professor of psychiatry and of human genetics in the University of Michigan Medical School. While the severity of symptoms can vary, people with ataxia have limited or no control over posture or coordination of their arms and legs.

"Because these disorders are so rare, it is difficult to collect DNA samples from enough affected individuals in different families with the same disorder to pinpoint the mutations that cause them," Burmeiser says. "Unless we can identify the mutated gene, it's hard to develop a diagnostic test or a therapy to help people with the disease."

A paper describing the research study will be published online October 12 by Nature Genetics, and will appear in the November issue of the journal. It is the result of a collaboration between scientists at the University of Michigan, the University of Miami, the University of Iowa and the National Human Genome Center at Howard University.

Before the U-M study, scientists knew that Cayman ataxia was caused by a recessive mutant gene originating in one of t
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Contact: Kara Gavin or Sally Pobojewski
kegavin@umich.edu
734-764-2220
University of Michigan Health System
12-Oct-2003