Is isolated Duane retraction syndrome inherited ?
Isolated Duane retraction syndrome usually occurs in people with no history of the disorder in their family. These cases are described as simplex, and their genetic cause is unknown.  Less commonly, isolated Duane retraction syndrome can run in families. Familial cases most often have an autosomal dominant pattern of inheritance, which means one copy of the altered gene in each cell is sufficient to cause the disorder. When isolated Duane retraction syndrome is caused by CHN1 mutations, it has an autosomal dominant inheritance pattern.  In a few families with isolated Duane retraction syndrome, the pattern of affected family members suggests autosomal recessive inheritance. In these families, one or more children are affected, although the parents typically have no signs or symptoms of the condition. The parents of children with an autosomal recessive condition are called carriers, which means they carry one mutated copy of a gene in each cell. In affected children, both copies of the gene in each cell are mutated. However, researchers have not discovered the gene or genes responsible for autosomal recessive isolated Duane retraction syndrome.