Intellectual Disability-Developmental Delay-Contractures Syndrome

Intellectual disability-developmental delay-contractures syndrome, formerly known as Wieacker-Wolff syndrome, is a severe X-linked recessive neurodevelopmental disorder characterized by severe contractures (arthrogryposis; see this term) and intellectual disability.

Epidemiology

Prevalence and incidence rates are not known. The syndrome has been reported in 5 families to date, with fewer than 30 affected individuals described. Affected patients are male, while carrier females are often asymptomatic. Cases have been reported from Germany, France, the Netherlands, Australia, and the United States.

Clinical description

The syndrome is characterized by an association of arthrogryposis multiplexa congenita and intellectual disability. Affected patients are born with severe contractures (arthrogryposis) and muscle weakness causing respiratory distress. Intellectual disability and delayed motor development are found in all patients. Facial weakness (ptosis) and bulbar weakness (feeding difficulty), characteristic dysmorphic facial features (possibly including long flat philtrum, low-set ears, high-arched palate, and carp-shaped mouth), and skeletal abnormalities (camptodactyly, hip dislocation, scoliosis, kyphosis, lordosis and pes equinovarus) have been reported. Other neurological signs may include spasticity and seizures. Heterozygous female carriers may also be affected, but to a lesser degree (intellectual disability, distal muscle weakness, camptodactyly, joint contractures, and pes equinovarus).

Etiology

Intellectual disability-developmental delay-contractures syndrome is caused by mutations in the ZC4H2 gene (Xq11.1) that is presumed to play a role in neuronal function during fetal growth.

Genetic counseling

The disorder follows an X-linked recessive pattern on inheritance. Simplex cases are also found. Genetic counseling should be provided to affected families.