The clinical presentation and radiogaphs are consistent with Multiple epiphyseal dysplasia. Figure A demonstrates short, stunted proximal femur with epiphyseal irregularities and incongruity of the femoral head. Figure B demonstrates a valgus left knee and flattened femoral condyles. Figure C shows shortened metacarpals and irregularities throughout the epiphyses of the metacarpals and phalanges. Multiple epiphyseal dysplasia is caused by a mutation in the COMP gene that leads to delayed and irregular ossification of the epiphyses of the long bones. Merritt et al. describes a novel technique of creating COMP mutations in vitro to study pseudoachondroplasia and MED. Rimoin et al. used electron microscopy and genetic anaylsis to exclude an entire family of loci as the potential genetic cause of MED and psuedoachondroplasia. Ballock et al. reviews the biology and function of the growth plate. Pelvis radiographs of MED are classically similar to Perthes disease, the key difference being that changes occur simultaneously in both hips in MED.
Merritt, TM, Alcorn JL, Haynes R, Hecht JT: Expression of mutant cartilage oligomeric matrix protein in human chondrocytes induces the pseudoachondroplasia phenotype. J Ortho Res 2006;24:700-707
PMID:16514635 (Link to Abstract)
Rimoin DL, Rasmussen IM, Briggs MD, Roughley PJ, Gruber HE, Warman ML, OlsenBR, Hsia YE, Yuen J, Reinker K, et al. A large family with features of pseudoachondroplasia and multiple epiphyseal dysplasia: exclusion of seven candidate gene loci that encode proteins of the cartilage extracellular matrix.Hum Genet. 1994 Mar;93(3):236-42.
PMID:7907311 (Link to Abstract)
Ballock RT, O'Keefe RJ. The biology of the growth plate. J Bone Joint Surg Am.2003 Apr;85-A(4):715-26
PMID:12672851 (Link to Abstract)