Natural History: Ellis van Creveld Syndrome [Note: the following summary of the natural history of Ellis van Creveld syndrome is neither exhaustive nor cited. It is meant to provide a guideline for the kinds of problems that may arise in children with this disorder, and particularly to help clinicians caring for a recently diagnosed child. For specific questions or more detailed discussions, feel free to contact the Midwest Regional Bone Dysplasia Clinic at the University of Wisconsin - Madison [608 262 9722; fax - 608 263 3496] Medical Issues and Parental Concerns to be anticipated Problem: Life Expectancy
Expectations: There is a residual risk of death in the newborn period or in infancy although this is much less than the previously estimated 50% risk. Aggressive evaluation and intervention regarding cardiac and pulmonary status will minimize these risks. No life tables have been generated but there is no a priori reason to anticipate a decreased life expectancy in those without severe heart and lung problems.
Expectations: Moderate to marked short stature; ultimate adult height between about 3 feet 7 inches and 5 feet 3 inches (110 to 160 cm). The origin of this marked variability is unknown.
Monitoring: Monitor growth to insure normal velocity. No diagnosis-specific growth standards are available.
Intervention: No interventions have been tried. Growth hormone etc. not likely to be effective since this disorder is secondary to intrinsic abnormality of bone growth. Limb lengthening in adolescence is a theoretical possibility.
Expectations: Central nervous system abnormalities including hydrocephalus, Dandy Walker malformation and other anomalies have been reported occasionally. Nonetheless, in general, cognitive function is normal unless other life threatening events intervene. Variations in developmental patterns are to be expected because of short stature, limitations of finger mobility, orthopedic complications etc.
Monitoring: Routine unless other clinical features suggest the presence of a CNS structural abnormality, in which case magnetic resonance imaging may be appropriate.
Expectations: Occurs in about 40-60% of affected individuals. Most frequently ASD [more than half] > single atrium > VSD > AV communis > other. This is the primary cause of death in infancy, but previous estimates of 50% mortality in this disorder did not take into account modern methods of management of cardiac and respiratory problems.
Monitoring: All affected infants need cardiologic assessment, including echocardiography as neonates.
Intervention: When heart disease is found, usual cardiac care is indicated. Aggressive and careful management of this problem takes precedence over virtually all other issues during infancy.
Expectations: At least three different respiratory problems may complicate infancy and early childhood. A constricted chest may cause chronic or intermittent hypoxemia secondary to restrictive lung disease. Less frequently laryngotracheobroncho-malacia may cause stridor, obstructive symptoms etc. A small minority of babies with this disorder seem to have central abnormalities of respiratory control (for unknown reasons).
Monitoring: Initial evaluation in infancy should at least include chest circumference, clinical assessment of respiratory status and polysomnographic evaluation.
Intervention: Depending on findings and the severity of abnormalities interventions that may be appropriate include home monitoring, parental training in CPR, oxygen supplementation, cpap or bipap, tracheostomy.
Problem: Ears and Hearing
Expectations: Conductive hearing loss probably occurs at increased frequency.
Monitoring: Behavioral audiometric screening should be completed by one year of age and then repeated yearly thereafter until school age.
Intervention: Usual methods of treating middle ear disease are appropriate. Occasional individuals will need hearing aids.
Expectations: Nearly constant postaxial polydactyly of the hands; infrequently of the feet.
Monitoring: Radiologic documentation of bone relationships should be completed prior to surgical removal.
Intervention: Removal of the extra digits surgically (not by simple ligation) is probably best done between around 2 years and 5 years of age.
Problem: Joint Limitation in the Hands
Expectations: This is secondary to abnormality of proportion and growth of the phalanges.
Intervention: None. Surgery is clearly contraindicated and may cause considerable harm.
Problem: Valgus Deformity
Expectations: Valgus or knock-knee deformity is secondary to asymmetric proximal tibial growth plate function. It is often quite severe, progressive and functionally debilitating.
Monitoring: Requires clinical monitoring throughout childhood. Radiologic and orthopedic assessment should be sought if valgus exceeds around 15°.
Intervention: Surgery is appropriate if the valgus results in instability, non-remitting pain, marked abnormality of gait etc. Surgical correction is by proximal tibial osteotomy (with either internal or external fixation). Surgery should be delayed as long as possible since recurrence is very likely given the primary cause. Repeat surgical intervention is frequently needed.
Problem: Other Orthopedic Problems
Intervention: Usually none.
Problem: Nail Abnormalities
Expectations: Usually markedly hypoplastic without significant growth. Relevance is cosmetic.
Intervention: None. Most often, artificial nails can not be adequately fitted.
Problem: Frenula, Pseudocleft of the Upper Lip, Alveolar and Gingivolabial Abnormalities
Expectations: While almost always present, these features infrequently are of clinical importance. They seem not to interfere with eating, speech development etc. However, gingivolabial adhesions/continuity may prevent appropriate prosthodontic fittings.
Monitoring: Determination by pediatric dentist and/or prosthodontist of need for intervention.
Intervention: Plastic surgical reconstruction if indicated.
Problem: Teeth Abnormalities
Expectations: Can include natal teeth (that usually should be removed), partial anodontia, malformed teeth, enamel and dentin abnormalities, predisposition to caries. Anodontia is particularly important with respect to articulation and to appearance and self-image.
Monitoring: Early involvement with a pediatric dentist is essential.
Intervention: Aggressive use of sealants, fluoride. Fitting for prosthetics as needed (including in childhood).
Expectations: Low incidence of structural abnormalities of the kidneys. Low incidence of renal tubular abnormalities.
Monitoring: Early renal ultrasound. Urinalysis and urine for amino acids to assess for general renal tubular function.
Intervention: Rarely needed.
Expectations: Considerable psychological and physical adaptive needs later in childhood. Anodontia may create psychological barriers if not appropriately treated. Many children seem to be bothered more by teeth and nail abnormalities than their limited growth.
Monitoring: Assess for age appropriate needs.
Intervention: Small stature may be sufficient to warrant adaptive interventions for toileting, school adaptations, stools, teacher involvement, Little People of America involvement. Psychological support as needed.
Genetics and Molecular Biology Ellis van Creveld syndrome appears always to be caused by an autosomal recessive gene abnormality. This means that parents of an affected child will have a 25% chance that each subsequent child will be similarly affected. No one else in the family should have significantly increased risk.
This disorder is considerably more frequent in certain genetic isolates including in the Amish.
The gene responsible for Ellis van Creveld syndrome has been mapped (to chromosome segment 4p16) but has yet to be identified.