Grebe type chondrodysplasia is a rare recessively inherited acromesomelic dysplasia clinically characterized by dwarfism with severe micromelia. Radiologically, it is characterized by short and deformed middle long bones, fusion of carpal bones and several metacarpal and metatarsal, and absence of proximal and middle phalanges. Other features include obesity and delayed mental development, but facial appearance and intelligence are normal with no vertebral abnormalities.
Grebe syndrome is associated with mutations in the CDMP1 gene, which encodes Growth/differentiation factor 5 (GDF-5). GDF-5 protein is a member of the bone morphogenetic protein (BMP) family and the TGF-beta superfamily.