multiple epiphyseal dysplasia (EDM)

Introduction

A genetic disorder of generalized skeletal dysplasia

Classification

• broadly categorized into
  • more severe Fairbank type
  • milder ribbing type

Pathology

• generalized skeletal dysplasia

Genetics

• associated with defects in COMP gene (type 1)
• recessively inherited form associated with defects in SLC26A2 (type 4)
• associated with defects in MATN3 (type 5)
• associated with defects in COL9A1 (type 6)
• associated with defects in COL9A2 (type 2)
• associated with defects in COL9A3 (type 3)

Clinical manifestations

• general
  • joint pain
  • joint deformity
  • waddling gait
  • short stature
• Fairbank type
  • shortness of stature
  • short & stubby fingers,
  • small epiphyses in several joints, including the knee, ankle, hand, & hip
• ribbing type
  • confined predominantly to the hip joints
  • hands are normal
  • stature that is normal or near-normal
• type 4
  • early childhood-onset hip dysplasia & recurrent patella dislocation
  • short stature is uncommon
• type 5
  • relatively mild & clinically variable
  • delayed & irregular ossification of the epiphyses
  • early-onset osteoarthritis

Laboratory

• cartilage oligomeric matrix protein in serum (type 1)

Radiology

• delayed, irregular mineralization of epiphyseal ossification centers & of the centers of the carpal bone & tarsal bone

Differential diagnosis

• less severe than pseudoachondroplasia (also resulting from defects in COMP gene)

More general terms

• skeletal dysplasia
• osteochondrodysplasia

More specific terms

• multiple epiphyseal dysplasia with myopia & conductive deafness

Additional terms

• cartilage oligomeric matrix protein; thrombospondin 5 (COMP, EDM1, PSACH, TSP5)

Database

• OMIM: https://mirror.omim.org/entry/132400
• OMIM: https://mirror.omim.org/entry/226900
• OMIM: https://mirror.omim.org/entry/614135
• OMIM: https://mirror.omim.org/entry/600204
• OMIM: https://mirror.omim.org/entry/600969
• OMIM: https://mirror.omim.org/entry/607078