Is EEC syndrome inherited ?
How is EEC syndrome inherited? EEC syndrome is inherited in an autosomal dominant manner.This means that having a change (mutation) in only one copy of the responsible gene in each cell is enough to cause features of the condition. In some cases, an affected person inherits the mutated gene from an affected parent. In other cases, the mutation occurs for the first time in a person with no family history of the condition. This is called a de novo mutation. When a person with a mutation that causes an autosomal dominant condition has children, each child has a 50% (1 in 2) chance to inherit that mutation. EEC can appear to be caused by a de novo mutation in some instances when an unaffected parent of an affected child has germline mosaicism. Germline mosaicism affects the genetic make-up of the egg and sperm cell only. It is estimated that unaffected parents of a child with EEC syndrome have a 4% risk of having another affected child. EEC syndrome additionally shows reduced penetrance and variable expressivity. Reduced penetrance means that not all individuals with a mutation in the disease-causing gene will have signs and symptoms of the condition; however, in this condition, it has been reported that up to 93-98% of individuals with a mutation will have the condition. Variable expressivity means that there is a range of signs and symptoms that can occur in different people with the condition (i.e. the expression of the condition varies).