This rare skeletal dysplasia was first described in 1940 by Richard W. Ellis and Simon van Creveld who coined the term “Chondroectodermal dysplasia” to illustrate the main features of this condition: ectodermal involvement (skin, hair and nails) and chondrodysplasia (cartilage and bone anomalies) (2).
Recent studies have found that mutations in two nonhomologous genes, positioned in a head-to-head configuration along chromosome 4 (4p16), are responsible for EVC (3).
Ellis-Van Creveld Dysplasia is most common in the Amish people of Pennsylvania and the indigenous people of Western Australia. The incidence is estimated at 1 per 60,000 live births. More than 200 cases of EVC have now been reported (3).
Face and Skull
- dental abnormalities: natal teeth, partial or pseudocleft in the middle upper lip, small teeth and delayed eruption
Trunk, Chest and Spine:
- no significant trunk abnormalities
- no spinal malformation
- occasional short thorax at birth
- short and narrow rib cage
What Are the X-Ray Characteristics?
The radiographic features of EVC patients include progressive distal shortening of the long bones, with metaphyseal broadening. In infancy, pelvic dysplasia is common, along with low iliac wings and downward projections at the medial and lateral aspects of the acetabula. Pelvis configuration will normalize by childhood. Delayed ossification of the upper lateral portions of the proximal tibia will cause knock-knee. In young childhood, the epiphyseal ossification center is adjacent to the middle portion of the tibial metaphysis. Hypoplasia of the lateral epiphyses also occurs. The carpals are malformed, with fusion of the capitate and hamate. The middle phalanges are short and broad; hypoplasia of the distal phalanges is typical.
The condition can be diagnosed in the first trimester of pregnancy through an ultrasound scan looking for extra fingers or toes, cardiac defects, abnormalities of the kidneys and under-developed limbs. It has to be distinguished from related disorders such as Jeune Syndrome and the short-rib polydactyly syndromes. This could be possible only after birth. Radiographic features might also help with the diagnosis.
Polydactyly will oftentimes require surgery so that the extra digit(s) can be removed. The surgery may be a soft-tissue or bony procedure, depending upon the underlying pathology.
Progressive Genu Valgus
Progressive genu valgus will require careful follow-up in the longer term, usually at 6-month to yearly intervals. Supporting the knee in a corrective knee brace is the initial management, but bracing does not obviate the need for surgery.
Surgery is advised for angulations greater than 20 degrees (less if the deformity is progressive in a young child). The bony deformity is corrected by an osteotomy and the leg is placed in an external fixator until the osteotomy heals. Recurrence over time is common and several corrective procedures may be necessary during childhood for severe deformities.
In the older child nearing the end of growth, an alternative strategy is to slow down growth of the inner aspect of the tibia by a metal staple or stop growth completely by surgical removal of the growth plate. Elevating the under-developed part of the tibia has been performed in selected cases to restore knee alignment.
Congenital Heart Defects
Congenital heart defects are seen in about 60 percent of children. The most common are an atrial septal defect, a single atrium, and a ventricular septal defect. Assessment by a pediatric cardiologist soon after birth is strongly recommended. Cardiac surgery may be needed to correct the abnormalities. Nearly 50 percent of babies born with EVC will die due to cardiorespiratory complications.
Genitourinary anomalies include poor development of the penis and kidneys. Evaluation by a pediatric urologist is advised.
Teeth will appear early and may even be present at birth. They are small, peg-shaped and poorly formed. EVC patients are predisposed to dental cavities. Several abnormalities around the lips and gums have been described. Children with EVC would benefit from early referral to an orthodontist for surgical or prosthetic management of dental problems.
Congenital heart disease is common, therefore cardiologist consultation
Occasionally, abnormalities such as mental retardation, renal anomalies, Dandy-Walker cysts, hydrocephaly, situs inversus, and heterotopic masses of grey matter, have been reported.
Finally, generally all skeletal dysplasias warrant multidisciplinary attention. Regular assessment by an orthopedist, geneticist, pediatrician,
dentist, neurologist, and physical therapist will provide the most comprehensive treatment.
- Jones, Kenneth L. Recognizable Patterns of Human Malformation. Philadelphia, PA: Elsevier Saunders. 2006.
- Scott, Charles I. Dwarfism. Clinical Symposium, 1988; 40(1):17-18.
- Spranger, Jurgen W. Brill, Paula W. Poznanski, Andrew. Bone Dysplasias: An Atlas of Genetic Disorder of Skeletal Development. Oxford: Oxford University Press. 2002.
From Nemours' KidsHealth
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Genetic tests are done by analyzing small samples of blood or body tissues. They determine whether you, your partner, or your baby carry genes for certain inherited disorders.
Genetic testing has developed enough so that doctors can often pinpoint missing or defective genes. The type of genetic test needed to make a specific diagnosis depends on the particular illness that a doctor suspects.
Many different types of body fluids and tissues can be used in genetic testing. For deoxyribonucleic acid (DNA) screening, only a very tiny bit of blood, skin, bone, or other tissue is needed.
Genetic Testing During Pregnancy
For genetic testing before birth, pregnant women may decide to undergo amniocentesis or chorionic villus sampling. There is also a blood test available to women to screen for some disorders. If this screening test finds a possible problem, amniocentesis or chorionic villus sampling may be recommended.
Amniocentesis is a test usually performed between weeks 15 and 20 of a woman's pregnancy. The doctor inserts a hollow needle into the woman's abdomen to remove a small amount of amniotic fluid from around the developing fetus. This fluid can be tested to check for genetic problems and to determine the sex of the child. When there's risk of premature birth, amniocentesis may be done to see how far the baby's lungs have matured. Amniocentesis carries a slight risk of inducing a miscarriage.
Chorionic villus sampling (CVS) is usually performed between the 10th and 12th weeks of pregnancy. The doctor removes a small piece of the placenta to check for genetic problems in the fetus. Because chorionic villus sampling is an invasive test, there's a small risk that it can induce a miscarriage.
Why Doctors Recommend Genetic Testing
A doctor may recommend genetic counseling or testing for any of the following reasons:
- A couple plans to start a family and one of them or a close relative has an inherited illness. Some people are carriers of genes for genetic illnesses, even though they don't show, or manifest, the illness themselves. This happens because some genetic illnesses are recessive — meaning that they're only expressed if a person inherits two copies of the problem gene, one from each parent. Offspring who inherit one problem gene from one parent but a normal gene from the other parent won't have symptoms of a recessive illness but will have a 50% chance of passing the problem gene on to their children.
- A parent already has one child with a severe birth defect. Not all children who have birth defects have genetic problems. Sometimes, birth defects are caused by exposure to a toxin (poison), infection, or physical trauma before birth. Often, the cause of a birth defect isn't known. Even if a child does have a genetic problem, there's always a chance that it wasn't inherited and that it happened because of some spontaneous error in the child's cells, not the parents' cells.
- A woman has had two or more miscarriages. Severe chromosome problems in the fetus can sometimes lead to a spontaneous miscarriage. Several miscarriages may point to a genetic problem.
- A woman has delivered a stillborn child with physical signs of a genetic illness. Many serious genetic illnesses cause specific physical abnormalities that give an affected child a very distinctive appearance.
- The pregnant woman is over age 34. Chances of having a child with a chromosomal problem (such as trisomy) increase when a pregnant woman is older. Older fathers are at risk to have children with new dominant genetic mutations (those caused by a single genetic defect that hasn't run in the family before).
- A standard prenatal screening test had an abnormal result. If a screening test indicates a possible genetic problem, genetic testing may be recommended.
- A child has medical problems that might be genetic. When a child has medical problems involving more than one body system, genetic testing may be recommended to identify the cause and make a diagnosis.
- A child has medical problems that are recognized as a specific genetic syndrome. Genetic testing is performed to confirm the diagnosis. In some cases, it also might aid in identifying the specific type or severity of a genetic illness, which can help identify the most appropriate treatment.
A Word of Caution
Although advances in genetic testing have improved doctors' ability to diagnose and treat certain illnesses, there are still some limits. Genetic tests can identify a particular problem gene, but can't always predict how severely that gene will affect the person who carries it. In cystic fibrosis, for example, finding a problem gene on chromosome number 7 can't necessarily predict whether a child will have serious lung problems or milder respiratory symptoms.
Also, simply having problem genes is only half the story because many illnesses develop from a mix of high-risk genes and environmental factors. Knowing that you carry high-risk genes may actually be an advantage if it gives you the chance to modify your lifestyle to avoid becoming sick.
As research continues, genes are being identified that put people at risk for illnesses like cancer, heart disease, psychiatric disorders, and many other medical problems. The hope is that someday it will be possible to develop specific types of gene therapy to totally prevent some diseases and illnesses.
Gene therapy is already being studied as a possible way to treat conditions like cystic fibrosis, cancer, and ADA deficiency (an immune deficiency), sickle cell disease, hemophilia, and thalassemia. However, severe complications have occurred in some patients receiving gene therapy, so current research with gene therapy is very carefully controlled.
Although genetic treatments for some conditions may be a long way off, there is still great hope that many more genetic cures will be found. The Human Genome Project, which was completed in 2003, identified and mapped out all of the genes (about 25,000) carried in our human chromosomes. The map is just the start, but it's a very hopeful beginning.
Reviewed by: Larissa Hirsch, MD
Date reviewed: September 26, 2016