TRAT1 and mulibrey nanism: To date, mutations in RBCC/TRIM family members have been shown to be causal in hereditary disorders of development, including mutation of MUL in mulibrey nanism, an autosomal recessive disorder involving defective development of several mesodermal tissues and MID1, in X-linked Opitz/GBBB syndrome, an inherited disorder primarily affecting midline structures as well as PYRIN/MARENOSTRIN, which is specifically mutated in familial Mediterranean fever [41]–[45].