Diagnostic criteria for FXTAS (fragile x associated tremor ataxia syndrome)

Molecular-- CGG repeat 55-200
Clinical
   Major intention tremor, cerebellar ataxia
   Minor  Parkinsonism, moderate to severe short term memory loss, executive function deficit
Radiologic
   Major white matter lesions in middle cerebellar peduncles (MCP sign)
   Minor  lesions in cerebral white matter, moderate to severe brain atrophy

Diagnostic categories

Definite-- one major clinical, and one major radiologic, or present inclusions at autopsy
Probable-- two major clinical, or one minor clinical and one major radiologic
Possible-- one major clinical and one minor radiologic