About Ellis-van Creveld Syndrome

How Is Ellis-van Creveld Dysplasia Inherited?

Ellis-van Creveld (EVC) is inherited in an autosomal recessive manner. This means that parents are typically of average stature and are both carriers of a change in an associated gene.

Talking to a genetic counselor can help families further understand how EVC is inherited.

What Causes Ellis-van Creveld Dysplasia?

Changes in either of two genes are associated with EVC. They are named EVC and EVC2, positioned in a head-to-head position along chromosome 4.

Physical Characteristics of Ellis-van Creveld Syndrome

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

X-Ray Characteristics

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.

How Is Ellis-van Creveld Dysplasia Diagnosed?

The condition can be suspected via a prenatal ultrasound noting extra fingers or toes, cardiac defects, small chest and short limbs.

EVC should be distinguished from related disorders such as Jeune Syndrome and other short-rib polydactyly syndromes. Genetic testing of EVC and EVC2 can confirm the diagnosis, before or after birth.

Associated Musculoskeletal Problems

Polydactyly

Polydactyly (extra fingers and/or toes) can be surgically removed if the family wishes.

Progressive Genu Valgus

Progressive genu valgum requires careful follow-up in the longer term. Bracing does not always remove the need for surgery.

Other Health Issues

Congenital Heart Defects

Congenital heart defects are seen in over half of children. The most common are atrioventricular septal defects. Assessment by a pediatric cardiologist soon after birth is strongly recommended. Cardiac surgery may be needed.

Teeth

Teeth can appear early and may even be present at birth. They can be small, peg-shaped and poorly formed, or missing completely, and can be predisposed to cavities. Several differences around the lips and gums have been described as well, including extra frenula. Children with Ellis-van Creveld syndrome would benefit from good dental care and early referral to an orthodontist for management.

What to Watch for With Ellis-van Creveld Syndrome

Congenital heart disease is common; therefore cardiologist consultation is strongly recommended at diagnosis.

Generally, all skeletal dysplasias warrant multidisciplinary attention. For individuals with Ellis-van Creveld syndrome, regular assessment by an orthopedist, geneticist, pediatrician, and dentist is ideal. Many will need close care by cardiology and pulmonary as well.