05/31/2026
Willow (Purranormal Will o the Wisp) and her brother Fig (Purranormal Fiddle Leaf Fig) really exemplify the difference in look between Contemporary (carrying a copy of the Burmese Head Defect gene) and Traditional Burmese. Both are lovely examples of the breed. Fig has a broad round face and a short muzzle compared to the average cat, and Willow's is even shorter and rounder or what we call "brachycephalic".
The Burmese Head Defect (BHD) gene is inherited in a codominant manner.
One copy (Heterozygous / Carrier): Cats usually develop a shortened, rounded face (brachycephaly) but do not suffer from any fatal defects. They will pass the mutation to 50% of their offspring.
Two copies (Homozygous mutated): Kittens are born with severe facial and skull malformations (frontonasal dysplasia). These deformities are fatal, and affected kittens are either stillborn or cannot survive and require euthanasia.
Genetic Testing & Management
Because the carrier state produces the more brachycephalic look that some people favor, the mutation has persisted in certain populations.
Responsible breeders rely on DNA tests to identify carriers and prevent fatal breedings (mating two carriers together results in a 25% chance of a homozygous kitten).
Though we have been and will continue to be primarily breeding traditional lines free of the BHD gene, the Contemporary Burmese population has been separated from Traditional for long enough that it provides an excellent source for "outcrossing" within the breed by mixing Traditional and Contemporary gene pools.
The kittens in this picture have a pedigree that boasts a co-efficient of inbreeding of only 0.03%. We know that while generally very healthy, the Burmese cat breed inherently has one of the lowest levels of genetic diversity among all pedigree cats, so studying pedigrees and making breeding choices such as this one is huge part of maintaining not only breed type, but more importantly, health.
