How is Antley-Bixler syndrome inherited?
Depending on the type of Antley-Bixler syndrome (ABS), it can be inherited in an autosomal dominant or autosomal recessive manner. An autosomal dominant condition occurs when a change to one copy of a gene is enough to cause the condition. Genes are found in cells and contain instructions that allow the body to function normally. They exist in pairs because one copy is inherited from the mother and the other copy from the father. An autosomal recessive condition occurs when changes to both gene copies cause the condition. This means that people with one altered gene do not develop the condition and typically do not have any symptoms. They are said to be carriers of the condition.
ABS has two inheritance patterns because the two types of ABS have different genetic causes. ABS without genital anomalies and disordered steroidogenesis is caused by a change to the FGFR2 gene and is autosomal dominant. Therefore, a change to one copy of the FGFR2 gene is enough to cause ABS. This type of ABS may be inherited from an affected parent or may be the result of a new change in that individual. Each child of an affected parent would have a 50% chance to inherit the altered copy of FGFR2 and thus be affected with ABS. ABS with genital anomalies and disordered steroidogenesis is due to changes in the POR gene and is autosomal recessive. Parents of an individual with this type of ABS are obligated carriers for the condition. If parents have one affected child, they are at 25% risk to have another affected child.
A genetic counselor can help you understand more about how ABS is inherited in your family. Genetic counselors can be found on the National Society of Genetic Counselors website.
Antley Bixler syndrome. (n.d.). Retrieved December 24, 2018, from https://rarediseases.info.nih.gov/diseases/5826/index