JMP syndrome is a rare autosomal recessive syndrome, classified as a proteosome-associated autoinflammatory syndrome (PRAAS), with joint contractures, muscular atrophy, microcytic anemia, and panniculitis-associated lipodystrophy. JMP is thought to be due to a mutation in the PSMB8 gene, affecting major histocompatibility complex (MHC) class I antigen processing. The few documented cases include 3 patients from Japan, 2 of which were born from consanguineous parents, 1 patient from Mexico, and 1 patient from Portugal.

Symptoms and signs present in infancy to adolescence with erythematous macules, papules, and panniculitic nodules, muscular atrophy, and severe panniculitis-induced lipodystrophy affecting the face, arms, and thorax. The muscular atrophy and lipodystrophy then progress to involve the abdomen and lower extremities. Other features documented across several case reports include microcytic anemia, periodic fever, basal ganglia calcification, hypergammaglobulinemia, hepatosplenomegaly, and cognitive delay. Case reports document patients living into their 40s, but no data has been reported on average life expectancy.