Table 1 Fragile X-associated tremor/ataxia syndrome FXTAS diagnostic criteria

Definite:

Radiological

One clinical major and one of the following:

Major

MRI white matter lesions in middle cerebellar peduncle and/or brain stem

 • one radiological major criterion

Minor

MRI white matter lesions in cerebral white matter

 • presence of intranuclear inclusion

Minor

Moderate to severe generalized atrophy

Clinical

Probable:

Major

Action tremor

One of the following:

Major

Cerebellar gait ataxia

Minor

Parkinsonism

 • two clinical major criteria

Minor

Moderate to severe short-term memory deficiency

 • one radiological major criterion and one clinical minor criterion

Minor

Executive function deficit

Pathological

Major

Classic FXTAS CNS intranuclear inclusions

Possible:

Both of the following:

 • one clinical major criterion

 • one radiological minor criterion