An autosomal recessive gene has been identified that causes a syndrome of meningoencephalocele and craniofacial deformity in Burmese cats.
The gene responsible is important in normal facial development. It appears that cats with one copy of the mutated gene may have some evidence of brachycephalia, but if two copies of the defective gene are present the full syndrome can develop with duplication of the upper jaw and incomplete formation of the skull. The defect is incompatible with life.
This defect appears to have arisen as a result of breeders selectively attempting to produce cats with a ‘rounder’ head, and may be limited to Burmese in the USA.
A genetic test is available to identify carriers of the ‘Burmese Head Defect – BHD’ gene.