Ellis-Van Creveld Syndrome

background

Ellis-van Creveld (EVC) syndrome is one form of the ectodermal dysplasias, a group of disorders that affect the embryonic ectoderm, which is the outer layer of the developing embryo. The ectodermal layer develops into many parts of a baby's body, including the eyes, skin, teeth, and bones, so in EVC syndrome these parts may not develop normally.
EVC syndrome primarily affects the bones. Symptoms associated with this disorder include short stature, short forearms and lower legs, and short ribs. Additional features may include extra fingers, toes, (called polydactyly), or both, and poorly developed nails and teeth. People with EVC syndrome also have a high incidence of certain heart problems, such as a single atrium.
EVC syndrome is caused by mutations or defects in the EVC or EVC2 gene. The normal functions of these genes are not yet known, but mutations result in abnormal protein synthesis.
Humans have 23 sets of chromosomes: 22 pairs of autosomes and one pair of sex chromosomes (females have two X chromosomes and males have one X and one Y chromosome). EVC syndrome is inherited, or passed down in families, as an autosomal recessive trait. This means that the defective genes are located on one of the 22 pairs of autosomes. In addition, two copies of the defective gene (one from each parent) must be inherited for the disease to appear. Individuals who inherit only one copy of the defective gene do not have the disease but are called carriers because they can pass the disorder to their children.
EVC syndrome is a rare disorder, occurring in about one out of 60,000-200,000 newborns worldwide. Males and females are affected in equal numbers. Incidence tends to be higher among the Old Order Amish in Lancaster County, Pennsylvania, where it occurs in about five out of 1,000 live births and two out of 1,000 living people. The prevalence of carriers in this population may be as high as 13%.
Other populations with a higher incidence of EVC syndrome include the indigenous people of Western Australia and people with English, Dutch, Jewish, Turkish, or French-Canadian heritage.
About half of patients with EVC syndrome die during infancy because of heart and breathing problems. Patients who survive infancy may have a normal life span. Those who survive tend to have normal intelligence. Maximum adult height is generally about 43-60 inches.

Related Terms

Autosomal recessive inheritance, chondroectodermal dysplasia, common atrium, disproportionate dwarfism, ectodermal dysplasia, EVC syndrome, EVC gene, EVC2 gene, mesoectodermal dysplasia.