Diagnostic Criteria for Nakajo-Nishimura Syndrome (NNS)

Genetic basis: mutation in PSMB8 (human proteasome subunit beta type 8) at p.G201V

Criteria:

(1) autosomal recessive inheritance

(2) pernio-like purplish rash of hands and feet during the winter or cold exposure

(3) nodular erythema with infiltration and induration

(4) repetitive spiking fever

(5) long clubbed fingers and toes with joint contractures

(6) progressive partial lipomuscular atrophy and emaciation (may be marked in upper body)

(7) hepatosplenomegaly

(8) calcification of the basal ganglia

A clinical diagnosis can be made when >= 5 of these criteria are present.

MRI shows multiple foci of myositis on T2 and on T1 with gadolinium enhancement.