Ellis-van Creveld syndrome is most common in the Old Order Amish population of Pennsylvania and the indigenous people of Western Australia, but have been reported around the world.
Face and Skull
- Hair may be absent/sparse/fine/silky
- Gums may form a pseudocleft in the middle upper lip
- Dental abnormalities, including natal teeth; small, misshapen, or missing teeth; and delayed eruption
Trunk, Chest and Spine
- Short ribs and narrow rib cage
- Exaggerated lumbar lordosis
Arms and Legs
- Disproportionate shortening of the limbs
- Polydactyly (extra fingers and sometimes toes)
- Decreased ability to make a fist, usually not a functional problem
- Hypoplastic/dysplastic toenails and fingernails
- Genu valgum (knock-knees), which can progress to limiting function
The radiographic features of those with Ellis-van Creveld syndrome include progressive distal shortening of the long bones (acromelic-micromelic).
Upper extremity findings include: radial head dysplasia and subluxation, and postaxial polydactyly with polymetacarpalia and synmetacarpalism can be present. The carpals can have fusion of the capitate and hamate, and there are frequently small distal phalanges.
In infancy, low iliac wings and downward projections at the medial and lateral aspects of the acetabula may be observed. Pelvis configuration will typically normalize by childhood with bone maturation.
Typical lower extremity findings include: round smooth femoral heads, moderate valgus of the upper femur, and severe valgus angulation of the tibia. Increased lateral sloping of the lateral tibial plateau with ‘‘cupping’’ and saucer-like depression of the lateral plateau is typical. Proximal medial tibial exostosis is frequently seen. Patellae lateral subluxation or dislocation is also common.