In other species: brown trout , dog , pig , taurine cattle , goat , rabbit

Categories: Craniofacial phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 112263 (gene) , 607223 (gene) , 125400 (trait)

Mendelian trait/disorder: unknown

Mode of inheritance: Multifactorial

Disease-related: yes

Key variant is published: no

Species-specific description: Information relating to the ALX1 variant, which causes in heterozygous animals an extreme brachycephalic phenotype (known as “Contemporary” Burmese) and in homozygous animals lethal frontonasal dysplasia (Lyons et al., 2016) has previously been listed here. The inforamtion has been moved to 'OMIA:002717-9685 : Frontonasal dysplasia, ALX1-related in Felis catus' [13/06/2023].

Mapping: Lyons et al. (2016) reported that a form of extreme brachycephalia and frontonasal dysplasia in Burmese cats mapped to chromosome B4. Details are provided at 'OMIA:002717-9685 : Frontonasal dysplasia, ALX1-related in Felis catus'. Bertolini et al. (2016) identified four ~1Mb regions of homozygosity peculiar to Persian cats (which are characterised by an extreme form of brachycephaly), one of which contains two genes "CHL1 and CNTN6 known to determine face shape modification in humans".

Clinical features: Brachycephaly in cats is characterised by a shortened head length (Gundemir et al. 2023). The shortening of the muzzle typically creates a 'squashed nose' appearance. Clinical features may include respiratory difficulties and airway obstructions due to normal sized nasal soft tissue structures in a reduced size cranium, kinking of the nasolacrimal ducts, and potential ophthalmic, neurological, dermatological, and reproductive issues - particularly in relation to abnormally-shaped skulls having difficulty passing through the birth canal (Schlueter et al., 2009). IT thanks DVM student Mon Wink, who provided the basis of this contribution in May 2023.

Breeds: British Shorthair (Cat) (VBO_0100052), Burmese (Cat) (VBO_0100053), Exotic Shorthair (Cat) (VBO_0100096), Himalayan (Cat) (VBO_0100117), Persian (Cat) (VBO_0100188), Scottish Fold (Cat) (VBO_0100209).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).