What is Apert Syndrome?

The following was developed from information contained in an article entitled Clinical Assessment and Multispecialty Management of Apert Syndrome, written by Lawrence C. Kaplan, MD, and published in Clinics in Plastic Surgery-Vol. 18, No. 2, April 1991. 

Major Features of Apert Syndrome

• Prematurely fused cranial sutures
• A retruded midface
• Fused fingers
• Fused toes

Possible Related Features of Apert Syndrome

These have been observed in some cases of Apert syndrome, although whether they were caused by Apert syndrome is uncertain.

• Various heart defects
• Dextrorotation
• Pulmonary Atresia
• Patent Ductus Arteriosus (PDA)
• Tracheoesophageal Fistula
• Pyloric stenosis
• Polycystic kidneys
• Bicornate uterus
• Hydrocephalus
• Ear infections
• Sleep Apnea
• Severe acne
• Increased incidence of eye injuries

Definition

Apert Syndrome is a genetic defect and falls under the broad classification of craniofacial/limb anomalies. It can be inherited from a parent who has Apert, or may be a fresh mutation. It occurs in approximately 1 per 160,000 to 200,000 live births. Apert syndrome is primarily characterized by specific malformations of the skull, midface, hands, and feet. The skull is prematurely fused and unable to grow normally; the midface (that area of the face from the middle of the eye socket to the upper jaw) appears retruded or sunken; and the fingers and toes are fused together in varying degrees. Apert syndrome is named for the French physician who first described it, E. Apert, in 1906.

In a normal child, the skull is made up of several "plates" which remain loosely connected to one another, gradually growing together to form the adult skull. The Apert child's skull, by contrast, has a premature fusion of these plates, restricting brain growth, and causing increased pressure in the brain as it grows. This is known as craniosynostosis. Early surgery relieves the pressures by allowing the plates to be detached from one another. During this early surgery some "cranial remodeling" may be done to give the child a more normal appearance.

The "retrusion" or hypoplasia of the midface is what could be described as a concave or dished in profile. As the skull grows, the upper and lower thirds of the face tend to grow at normal rates, but the middle third of the face grows slower, resulting in a more pronounced retrusion over time. A surgical procedure known as the LeFort III is used to correct this condition. The procedure is usually done after substantial growth is complete (preadolescence) and may be repeated as necessary. The LeFort procedure involves detaching the facial bones from mid eye to upper jaw and spacing this area out with bone grafts so that a proper alignment is made.  In the last few years, some surgeons have come to prefer the Rigid External Distraction (RED) system or internally placed distractors, instead of or in conjunction with, traditional craniofacial surgery.

The fusion of the fingers and toes along with the craniofacial problems mentioned above is what really separates Apert from other similar syndromes. This condition is called syndactyly. It always involves fusion of the soft tissues of the first, middle, and ring fingers, and often there is fusion of the bones themselves. Joint mobility is usually nonexistent past the first joint. The thumb may be fused into the hand, or may be free. Surgery is used to separate the fingers to obtain the highest degree of functionality, and may or may not ultimately result in five digits on each hand. It varies according to the degree of malformation. The feet and toes are affected similarly, but surgery is usually only recommended in cases where the ability to walk would be impaired.

Ideally, treatment of Apert begins at birth with the proper diagnosis, identification of the child's individual needs, and the proper facilities to administer what is needed. A multidisciplinary approach is used by physicians in the best arrangements. A craniofacial anomalies team may consist of a craniofacial surgeon, neurosurgeon, ENT, audiologist, speech pathologist, oral surgeon, psychologist, ophthalmologist, and an orthodontist. The team approach is used by these physicians to determine the best collaborative corrective plan for the deficiencies of the child.

Genetics

Apert syndrome is a result of genetic mutation. When you have Apert syndrome, you have a 1 in 2 (50%) chance of passing this condition to your child. This is because each of us gets 1/2 of our genetic makeup from each parent. However, Apert is not a recessive trait, which means that the UNaffected child of a parent with Apert syndrome is no more likely to have a child with Apert than any other person; also, if you have a child with Apert and you do NOT have Apert, YOU are no more likely to have another child with Apert than anyone else in the population. Studies have shown that Apert occurs more often in children of older fathers.

Recently studies were conducted at Oxford University and they managed to identify the actual genetic change which occurs in Apert. The following is a quote from a letter sent to the test families by Oxford.

"A total of 86 children and adults affected with Apert syndrome have been seen. From the blood samples which have been donated for research, we have identified the genetic change that causes the condition. The change is in a gene on chromosome number 10 called 'Fibroblast Growth Factor Receptor 2' (FGFR2 for short). We all have two copies of this gene (one from mother, one from father), which is composed of a string of about 2000 of the chemical building blocks that make up the genetic material called DNA. When Apert syndrome occurs, just one particular building block in one of these two gene copies has been exchanged for another. The other gene copy is entirely normal. This one tiny change in the FGFR2 gene results in the physical features of Apert syndrome."