Apert syndrome is a form of acrocephalosyndactyly, a congenital disorder characterized by malformations of the skull, face, hands and feet.

In the case of acrocephalosyndactyly, selective cell death does not occur and skin, and rarely bone, between the fingers and toes fuses.

Findings for the incidence of the syndrome in the population have varied,[3] with estimates as low as 1 birth in 200,000 provided[4] and 160,000 given as an average by older studies.

[7] Another study conducted in 2002 by the Craniofacial Center, North Texas Hospital for Children, found a higher incidence of about 1 in 65,000 live births.

Due to the premature closing of the coronal sutures, increased cranial pressure can develop, leading to mental deficiency.

A flat or concave face may develop as a result of deficient growth in the mid-facial bones, leading to a condition known as pseudomandibular prognathism.

[11] The hands in patients with Apert syndrome always show four common features:[12] The deformity of the space between the index finger and the thumb may be variable.

An omphalocele is a birth defect in which an intestine or other abdominal organs are outside of the body of an infant because of a hole in the bellybutton area.

Wilkie published a paper showing evidence that acrocephalosyndactyly is caused by a defect on the fibroblast growth factor receptor 2 gene, on chromosome 10.

[15][16] Apert syndrome is an autosomal dominant disorder; approximately two-thirds of the cases are due to a C to G mutation at the position 755 in the FGFR2 gene, which causes a Ser to Trp change in the protein.

There has been one study that suggests it has something to do with the expression of three isoforms of FGFR2, the gene with the point mutations that causes the syndrome in 98% of the patients.

[citation needed] Diagnosis is typically by the apparent physical characteristics and can be aided by skull X-ray or head CT examination.