What is Ellis Van Creveld Syndrome?
Ellis-van Creveld (EVC) syndrome is a rare inherited genetic disorder which affects a person’s stature to be short or in other words, dwarfism. It occurs when EvC or EvC2 genes present in primary cilia is having a defect. People with Ellis-van Creveld syndrome has relatively short legs, forearms, and rib cages . Rib cages are narrow in people with this syndrome.
Ellis-van Creveld syndrome is also accompanied by Polydactyly, that is protuberance of the extra finger(s) and/or Toe(s). There are other characterizations of Ellis-van Creveld syndrome like dental abnormalities, fingernails and toe deformities. Most of the people born with Ellis-van Creveld syndrome tend to have heart problems which can be seriously fatal.
Symptoms of Ellis Van Creveld Syndrome
Symptoms of Ellis-van Creveld syndrome include the following:
- Dwarfism as the Most Important Symptom of Ellis-van Creveld Syndrome: Dwarfism is a condition of short stature. Height of an individual which is less than 4ft as an adult is considered a dwarf. It is often characterized by short size torso, short arms, and legs, short trunk with relatively larger limbs.
- Short Arms and Legs: Arms and legs are apparently shorter than normal people.
- Orofacial Cleft: Orofacial cleft occurs when a baby’s lip or mouth is not developed properly during pregnancy. In orofacial clefts, the tissue that makes the roof of the mouth is not able to join properly during pregnancy.
- Cryptorchid as a Symptom of Ellis-van Creveld Syndrome: Cryptorchid is basically a condition of undescended testicles where one or both testicles have not moved down to the scrotal sac. This condition is common in premature babies as their testicles do not descend down to scrotal sac from abdomen until the 7th month of development of foetus.
- Polydactyly: Polydactyly is a condition where a person is born with an extra finger or toe. Possibility of occurrence of extra fingers can be on both hands and/or both feet.
Limited Body Movement: A condition in which body movement is relatively limited than a normal person.
- Abnormal Nail Growth as a Symptom of Ellis-van Creveld Syndrome: Abnormal nail growth can include vertical ridges or brittle patches. Nail discoloration is also possible in some cases.
- Hair: Fine textured hair is either sparse or completely absent.
- Teeth Abnormalities as a Symptom of Ellis-van Creveld Syndrome: Teeth abnormalities include wide gaps between teeth, disproportionate alignment of teeth, pegged teeth, over or undergrowth of teeth.
Associated Complications of Ellis-Van Creveld Syndrome
The problems associated with Ellis van Creveld syndrome include the following:
- Abnormalities in Bone Growth: Abnormalities in bone growth refers to abnormal growth of arms, legs, ribs, and so on.
- Kidney Disease: Kidney disease may occur in some cases of Ellis-van Creveld Syndrome which can be life-threatening sometimes.
- Congenital Heart Disease (CHD): Congenital heart disease is related to the structure of heart from birth itself where the arteries and veins near the heart, the valves, and the walls are commonly affected. This can disrupt the flow of blood and the proper functioning of the heart. Apart from these defects, the heart may have a hole or in some cases multiple holes in it.
- Breathing Problems: Due to narrow rib cages or abnormal cardiac muscle, the person may face breathing problems.
- Improper Alignment of Teeth: Improper alignment of teeth can result in oral infections, difficulty in chewing the food, communication problem and breathing problem.
- Protrusion of Extra Finger or Toe: Protrusion of extra finger or toe, in other words, polydactyly is also very common.
Epidemiology of Ellis Van Creveld Syndrome
Ellis-van Creveld syndrome is a very rare genetic disorder which occurs to 1 in every 60,000 to 200,000 births. It is much more common in older people in the Amish community of Pennsylvania and in native parts of Western Australia.
The Pattern of Inheritance of Ellis Van Creveld Syndrome
The pattern of inheritance is Autosomal Recessive Pattern which means both the genes inherited by the parents has been mutated. However, they may not generally show the symptoms of the condition.
Causes of Ellis-van Creveld Syndrome
Ellis-van Creveld syndrome is caused by mutations in EvC or EvC2 gene; in other words, it is inherited by an autosomal recessive genetic condition, which occurs when an individual receives two copies of the abnormal gene, one from each parent who carries the same trait. In case the foetus receives one normal gene and another one with the disease, then the child will become a carrier but not suffer from it themselves.
Not much is known about the working of EvC or EvC2 genes. These genes appear to play a key role in cell-to-cell signaling or creating a Sonic Hedgehog signaling pathway during the development. The pathways play a vital role in the growth of the cell, specialization of cell and proper formation of the parts of the body.
The mutations which result in Ellis-van Creveld syndrome are the production of an abnormally small, dysfunctional form of EvC or EvC2 protein. Although, it is not clear how these defective proteins result in such signs and symptoms of this condition.
Studies say that these defective proteins interfere with the Sonic Hedgehog signaling pathways in the developing embryo which leads to deformity and disruption in the growth of bones, teeth and other parts of the body.
In most of the cases of Ellis-van Creveld syndrome, mutations of EvC and EvC2 genes leads to the syndrome, as for the rest of the cases, the cause still remains unknown.
Diagnosis for Ellis-Van Creveld Syndrome
Diagnosis for Ellis-van Creveld syndrome is done with the help of a few tests. The tests include:
Genetic testing might be performed for mutations in one of the EvC genes.
Treatment for Ellis Van Creveld Syndrome
It is to be noted that Ellis-van Creveld Syndrome cannot be treated by any means. However, the complications can be treated that too depending upon the severity of the problem the body is affected with.
Prognosis of Ellis Van Creveld Syndrome
In most of the cases, the babies with EVC die in an early stage of infancy. The reason of this is the small chest and the defect in the heart like a hole in the heart. In such cases, stillborn is also quite common.
The result relies on the part of the body involved and to what extent. For example, most of the genetic conditions involve bones or physical structure, whereas intelligence is normal.
Ellis-van Creveld syndrome is a very rare autosomal recessive disorder which leads to dwarfism, bone deformities etc. People with Ellis-van Creveld syndrome may have involvement of multiple complications such as CHD, abnormal bone growth, misaligned teeth, etc. The defect cannot be treated or cured but the associated bodily problems can be treated. The treatment includes full body examination, preoperative evaluation, cardiac evaluation, pulmonary evaluation of the body. People with Ellis-van Creveld require multiple surgeries throughout their lives. Managing people with Ellis-van Creveld syndrome is very difficult when it comes to restorative care or preventing oral diseases. In some cases, like cardiac deformity, it can be very fatal. Ellis-van Creveld syndrome has a very high mortality rate as in early life i.e., nearly 1 out of 3 patients die in the early infancy stage and stillborn is also quite common. The ones who survive require a very comprehensive approach to treatment. Treatments can only be commenced depending on the severity of the condition. However, early diagnosis and treatment can prevent the patient from various complications and undue psychological distress.
- Hassona, Y., Hamdan, M., Shqaidef, A., Abu Karaky, A., & Scully, C. Ellis-Van Creveld syndrome: dental management considerations and description of a new oral finding. Special Care In Dentistry, (2015). 312-315.