PSMB8 encoding the [beta]5i proteasome subunit is mutated in joint contractures, muscle atrophy, microcytic anemia, and panniculitis-induced lipodystrophy syndrome

Homozygosity mapping results for two pedigrees from Portugal and Mexico with an autosomal-recessive auto-inflammatory syndrome characterized by joint contractures, muscle atrophy, microcytic anemia and panniculitis-induced lipodystrophy (JMP) are presented. The study results suggested that mutations in PSMB8 cause JMP syndrome, most possibly by affecting MHC class I antigen processing.