Dysplasia epiphysealis hemimelica

What it is

A rare bone development disorder characterized by localized, asymmetric osteochondral overgrowth affecting single or multiple epiphyses, most commonly the distal femur, proximal tibia, and talus. The lesions are typically restricted to one side of the epiphysis, with the medial side being affected twice as often as the lateral side. The condition is usually diagnosed in children, and three times more often in boys than in girls. Patients present with pain, limitation in range of motion, and deformity or swelling of the affected joint.

Key facts

Prevalence

1-9 / 1 000 000 (annual incidence)

Age of onset

Adolescent, Childhood

Inheritance

Autosomal dominant

Classified as

Malformation syndrome

Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.

Signs and symptoms

These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.

ICD-10 codes

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Cross-references