Antley-Bixler Syndrome

Antley Bixler syndrome is a rare condition that is primarily characterized by craniofacial abnormalities and other skeletal problems. The signs and symptoms vary significantly from person to person but may include craniosynostosis; midface hypoplasia (underdeveloped middle region of the face); frontal bossing; protruding eyes; low-set, unusually-formed ears; choanal atresia or stenosis (narrowing); fusion of adjacent arm bones (synostosis); joint contractures; arachnodactyly; bowing of the thigh bones; and/or urogenital (urinary tract and genital) abnormalities. The exact underlying cause of Antley Bixler syndrome is unknown in many cases; however, some are due to changes in the FGFR2 gene or the POR gene. There appear to be autosomal dominant and autosomal recessive forms of the condition.

Genetic Mutations: Antley-Bixler syndrome is caused by genetic mutations, also known as pathogenic variants. Genetic mutations can be hereditary, when parents pass them down to their children, or they may occur randomly when cells are dividing. Genetic mutations may also result from contracted viruses, environmental factors, such as UV radiation from sunlight exposure, or a combination of any of these.

If you suspect you may have this disease, you may want to start collecting your family health history. Information such as other family members who have had similar symptoms, when their/your symptoms first appeared, or exposures to any potential disease-causing environmental factors should be discussed with your medical team.

Yes. It is possible for a biological parent to pass down genetic mutations that cause or increase the chances of getting this disease to their child. This is known as inheritance. Knowing whether other family members have previously had this disease, also known as family health history, can be very important information for your medical team.

There are multiple ways, or patterns, a disease can be inherited depending on the gene(s) involved. Based on GARD’s current data, this disease can be inherited in the following pattern(s):

Autosomal Dominant: Autosomal means the gene involved is located on one of the numbered chromosomes. Dominant means that a child only needs to inherit one copy of the mutated gene, from either biological parent, to be affected by the disease.

People affected by an autosomal dominant disease have a 50% chance of passing on the mutated gene to their biological child.

Autosomal Recessive: Autosomal means the gene involved is located on one of the numbered chromosomes. Recessive means that a child must inherit two copies of the mutated gene, one from each biological parent, to be affected by the disease. A carrier is a person who only has one copy of the genetic mutation. A carrier usually doesn’t show any symptoms of the disease.

If both biological parents are carriers, there is a 25% chance their child inherits both copies of the mutated gene and is affected by the disease. Additionally, there is a 50% chance their child inherits only one copy of the mutated gene and is a carrier.