Brachycephaly / Frontonasal dysplasia / Burmese Head Defect (ALX1-related) - Cat

Burmese Head Defect and frontonasal dysplasia

This genetic test analyses the ALX1 deletion c.496delCTCTCAGGACTG in cats. The variant is known in Burmese cats and is linked to the spectrum of brachycephaly, frontonasal dysplasia (FND) and Burmese Head Defect (BHD).

With one copy, the variant causes the pronounced short, rounded head type known in some Burmese lines as “Contemporary Burmese”. With two copies, the variant causes severe frontonasal dysplasia with major malformation of the skull and face.

Practical value of this test

• Shows whether a cat is clear, heterozygous or homozygous for the ALX1 deletion.
• Helps breeders avoid combinations that can produce homozygous affected kittens.
• Provides useful information for selection around head type, breed line and health risk.

This variant is described as autosomal co-dominant: heterozygotes show a milder head type, while homozygous kittens are severely affected.