Apert Syndrome

What is Apert syndrome?

Apert syndrome is a genetic disorder characterised by the premature fusion of certain bones of the skull (craniosynostosis), which prevents further growth of the skull and affects the shape of the head and face. In addition, a varied number of fingers and toes are fused together (syndactyly).

Many of the characteristic facial features of Apert syndrome result from the premature fusion of the skull bones. The head is unable to grow normally, which leads to a sunken appearance in the middle of the face, bulging and wide-set eyes, a beaked nose, and an underdeveloped upper jaw leading to crowded teeth and other dental problems. Shallow eye sockets can cause vision problems. Hearing loss may be present. Recurrent ear infections are common and may be associated with an opening in the roof of the mouth (cleft palate). Acne can be severe. Additionally, individuals with Apert syndrome have webbed or fused fingers and toes. The severity of the fusion varies; at a minimum, three digits on each hand and foot are fused together. In the most severe cases, all of the fingers and toes are fused. Intellectual development also varies, ranging from normal to mild or moderate mental retardation.

How common is Apert syndrome?

Apert syndrome affects about 1 in 100,000 individuals.

What genes are related to Apert syndrome?

Mutations in the FGFR2 gene cause Apert syndrome.

The FGFR2 gene produces a protein called fibroblast growth factor receptor 2. Among its multiple functions, this protein signals immature cells to become bone cells in a developing embryo and foetus. A mutation in a specific part of the FGFR2 gene alters the protein and causes prolonged signaling, which can promote the premature fusion of bones in the skull, hands, and feet.

How do people inherit Apert syndrome?

Apert syndrome is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Almost all cases of Apert syndrome result from a sporadic new mutation, meaning neither parent has the disorder. Individuals with Apert syndrome, however, can pass along the disorder to the next generation.

What other names do people use for Apert syndrome?

* Acrocephalosyndactyly (Apert)