CAT GENES AND GENE SYMBOLS

This page simply lists the symbols for commonly referenced genes for colours, patterns and anomalies. Where there are several alleles, these are listed in order of dominance (some are co-dominant) though the order of dominance for posited genes is unknown. Although most of the traits/genes listed here are shown as dominant/recessive, some traits once thought to be controlled by simple Mendelian inheritance principles are actually influenced by one or more modifier genes.

Some genes are hypothetical or under debate i.e. an effect has been observed, but the existence of a single gene governing that effect has not been proven.

BASIC COLOUR GENES

There are two types of colour pigment - eumelanin (black/brown pigment) and phaeomelanin (yellow/red pigment). There are several mutant forms of the black/brown pigment. The coat colour depends on which pigments are present. A number of other genes modify the amount of pigment in the hair shaft and whether it is laid down in alternating light and dark bands along the shaft or as a single, solid band stretching from follicle to hair tip. At the foot of this page there is a more detailed description of how melanin works to give a wide array of colours.

 

Dominant

Recessive(s)

Notes

Colour/Albino

C - full colour

c - pink-eyed albino
ca - blue-eyed albino
cb- Burmese
cm- Mocha
cs - Siamese

cscb = Tonkinese
cscm = Siamocha
cbcm = Burmocha

Agouti

A - agouti

a - non-agouti

Wild-type is agouti

Agouti - Charcoal Pattern

a + APb = Charcoal Pattern

A2 = Agouti variant found in Bengal and Savannah cats. The phenotypic effect of A2 has not been established.
APb = alternative Agouti variant found in Asian Leopard Cats.
ALs = alternative Agouti variant found in Serval and Savannah cats. The phenotypic effect of ALs has not been established.

Black/brown

B - black/brown

b - chocolate
bl - cinnamon

Order of dominance is B > b > b1

Dilution

D - dense

d - dilute

 

Orange

O

o - wild-type

Sex-linked

White Masking / Spotting

W - White masking (masks all other colours)
Ws - piebald/white spotting (recessive to white masking)

w - non-white
wg white gloving

Epistatic

 

Colour Modifier Genes

These are genes that modify the action of other genes giving more subtle variations on the basic colour. Although it could be argued that dense/dilute modifies the colour, it is listed as a basic colour.

 

Dominant

Recessive

Notes

Amber (Extension Gene/Black Modifier)

E - black pigment produced

e -red pigment produced

ee genotype produces reddish pigment instead of black or blue

Dilute Modifier

Dm - modifies dilute colours

dm - no effect on colour

Dominant, but only affects cats that are homozygous for dilute "d"

Pink Eye Dilution

??

??

Recessive? Turns Black into a light brown colour, eyes are golden with red pupil.

Colour Inhibitor

I - gives silver undercoat

i (i+) - no silver undercoat

Dominant gene giving silver undercoat, works in conjunction with Wideband (Wb) in tipped, shaded and smoke phenotypes

Sunshine (Siberian Golden)
See Wideband wbSIB

sg - old terminology for WBSIB

Recessive gene in Siberian (possibly also Kurilian) breed currently only seen in agouti (tabby patterned) Siberian cats where it produces reddish areas in the black, blue etc coat. Because Sunshine is on a different locus to the Inhibitor (silver) gene (or polygenes), it is possible for both genes to occur in the same cat resulting in a "bi-metal" appearance where both silver and golden areas are present.

Wideband

wb - wideband effect
wbBSH - Flaxen Gold (British)
wbSIB - Sunshine (Siberian)
wbBEN - Sorrel (Bengal)

WB is also called VWB - Variable Wideband, VWB+ being the "wild type")

Determines width of silver/gold undercoat band between hair follicle and first band of pigment. Inherited independently of Silver
homozygous wbBSH is Flaxen Gold in British
homozygous wbSIB is Sunshine in Siberians
homozygous wbBEN is Sorrel in Bengals

 

PATTERN GENES

Colourpoint is not included here as it is a form of albinism. These genes affect the distribution of colour on the body. Some of the posited genes have been given symbols by breeders, but are not widely accepted. You will find that outdated texts give Ta as ticked tabby, Tm as mackerel tabby and Tc as classic tabby and describe them as alleles of a single "tabby" gene. This was later proved incorrect. Tm and Tc are no longer used; mackerel is now Mc and classic tabby is mc. Ticked tabby is a different gene and remains Ta although some early research designated it U for "unstriped tabby".

 

Dominant

Recessive

Notes

Altai Blue Eyes

??

 

Dominant, causes blue eyes.

Bengal Glitter

 

gl

 

Melanin Inhibitor

I - silver

i (i+)

Silver (ii [or --] + Wb = gold)

Ojos Azules

??

 

Dominant, causes blue eyes and white splashed extremeties

Spotted Tabby

Sp

 

Egyptian Mau type spots

Tabby Pattern

Mc- mackerel
Ms - spotted

mc - classic

 

Tabby Pattern Modifier - size

Thl - large pattern classic tabby

ths - small pattern classic tabby (Sokoke type)

Posited for Australian Mist, interacts with mackerel or classic tabby to determine blotch size/density

Tabby Pattern Modifier - spots

Pmf - modified tabby

pmu - unmodified tabby

Posited for Australian Mist, interacts with mackerel or classic tabby to give small or large spots respectively

Ticked Tabby
(Unstriped Tabby)

T a- Abyssinian ticked
U (alternative notation for Unstriped)

ta - non Aby ticked
u (alternative notation for "does not mask striped pattern")

Originally thought to be an allele of Tabby Pattern, but now known to be on a different locus

White Masking / Spotting

W - White masking
Ws - piebald/white spotting (recessive to white masking)

w non-white
wg white gloving

Sb and Sm are posited modifiers.
Mitted breeds other than Birmans might not have the wg "White Gloving" gene, but a different mutation. Previously N was used for non-gloved

 

FUR TYPE GENES

These are fur type anomalies that are (or have been) selectively bred; some of the newer ones have not been allocated symbols. At the time of writing there are also several "new" rexes whose genetic make-up has not yet been determined.

 

Gene Symbol

Notes

Cornish Rex

r

recessive

Devon Rex

re

recessive
Sphynx & Devon Rex are different mutations of the same allele (same locus. Devon Rex is recessive to Sphynx.)

Dutch Rex

Rd

dominant

German Rex

gr

recessive

Long hair

l

recessive

Hairless (French)

h

recessive

Haired

Hr

Dominant to Sphynx Hairless, recessive to Russian Hairless

Hairless (Hawaiian)

hr

DNA analysis found this to be same mutation as Sphynx with other effects being due to interaction/recombination of genes on other loci

Hairless (Mexican)

??

Never identified, research in newspapers has found that this term was a generic name for early hairless cats regardless of parentage or geographical origin.

Hairless (Redcar hairless)

hd

Recessive, lethal (British hairless mutation)

Hairless Russian (Peterbald & Donskoy)

Hrbd

dominant (incomplete penetrance)
Hrbd (bald) - Russian Hairless Gene has 2 modifiers:
hi mInimiser modifier for Improving hairlessness
ha mAximiser modifier for constraining/weakening hairlessness

Combinations:
HrHr + hiha = normal haired (assume one of each modifier)
HrbdHr + hihi = brush coat
HrbdHr + hiha = brush coat with some bald areas
HrbdHr + haha = brush coat that turns bald
HrbdHrbd + hihi = velour coat
HrbdHrbd + hiha = flocked coat
HrbdHrbd + haha = rubber bald born bald and remains bald

Hrbd > Hr >hr
Russian Hairless > Haired > Sphynx hairless (recessive)

Hairless (Sphynx)

hr

Recessive; Canadian Sphynx breed.
Sphynx & Devon Rex are different mutations of the same allele (same locus). Sphynx is dominant to Devon Rex.

LaPerm

Lp

dominant

Oregon Rex

ro

recessive

Recessive Shorthair

??

recessive. Shorthair is normally dominant over longhair, but some Persian lines (should breed true for recessive longhair gene) have produced shorthair offspring.

Satin (Tennessee Rex)

??

either recessive or "dominant with additive effect". Homozygotes have "radical satin" fur (and are also curly haired) while heterozygotes (straight haired "carriers" of Tennessee Rex curled fur) have shinier-than usual fur, but not a high degree of satin. It isn't established whether the satin and rex traits are caused by one gene or by two genes located close to each other.

Selkirk Rex

Se

dominant (the symbol Rs has also been used)

Sparse (Lykoi)

hrTN
hrVA
hrTX

hrFR
hrNC
hrCa

Tennessee & Missouri lineages
Virginia lineage
Texas, California, Georgia, South Carolina, Utah, Vermont, Florida 2 & France 2 lineages
France 1 lineage
North Carolina lineage
Canada & Florida 1 lineage

Wirehair

Wh

Dominant (poss incomplete)

York Choc Undercoat

Yuc
yuc

Dominant, lacks undercoat (posited)
Recessive, full undercoat (posited)

 

BODY TYPE GENES

These are conformation anomalies that are selectively bred.

 

Gene Symbol

Notes

Bobtail (Japanese, Karelian)

Jb

Recessive
The gene itself is autosomal dominant, however, homozygous recessive cats have the desired bobtailed trait therefore breeders treat the gene as though it were recessive.

Bobtail (Kurelian)

??

Incomplete Dominant

Curled Ear

Cu

dominant

Folded Ear

Fd

Dominant, incomplete penetrance

Manx

M

dominant

Munchkin

Mk

dominant

Polydactyl

Pd

Incomplete penetrance (this is "classic polydactyly"; there may also be other mutations producing polydactyly

Ringtail

??

A recessive gene controls the degree of curl.
An incomplete dominant gene controls how the tail is carried.

 

 ABNORMALITIES

This list excludes those abnormalities that have been developed as breed traits. The list includes both physical and physiological anomalies.

Abnormality

Gene Symbol

Notes

Brachyury (short tail)

br

recessive

Chediak-Higashi syndrome

ch

Recessive

Cutaneous asthenia ("winged cat syndrome")

Cut

dominant

Episodic weakness

ew

Recessive (provisional symbol)

Flat Chested

fck

Recessive (provisional symbol)

Four Ears (duplicate pinnae)

dp

Recessive

Gangliosidosis GM1

ga-1

recessive

Gangliosidosis GM2

ga-2

recessive

Haemophilia A

Hma

Sex-linked

Haemophilia B

Hmb

Sex-linked

Hageman Factor Deficiency

Hag

Dominant (incomplete)

Hydrocephaly

hy

recessive

Hyperoxaluria

ho

recessive

Hyperchylomicronemia

hce

recessive

Mannosidosis

man

recessive

Meningoencephalocele

mc

recessive

Mucopolysaccharidosis-1

mps-1

recessive

Mucopolysaccharidosis-6

mps-6

recessive

Mucopolysaccharidosis-7

mps-7

recessive

Neuroaxonal dystrophy

no

recessive

Pelger-Huet Anomaly

Ph

Dominant

Polycystic Kidney Disease

??

 

Porphyria

Po

Dominant

Progressive Retinal Atrophy

rdg

Recessive (Sweden)

Progressive Retinal Atrophy (Rod-Cone Dysplasia)

Rdy

Dominant (UK)

Retinal degeneration

rt

recessive

Short Rounded Ears (with neurological syndrome)

??

recessive

Sparse fur

sp

recessive

Spasticity

spt

Recessive

Spheroid lysosomal disease

si

recessive

Sphingomyelinosis

spi

Recessive

Split Foot (syndactyly)

Sh

Dominant

Testicular feminisation

tfm

Recessive

Tremor

tr

Recessive

 

HOW MELANIN PRODUCES MANY COLOURS

Colour is caused by the melanin pigment. There are two distinct types of melanin in the cat: eumelanin (black-based) and phaeomelanin (red/yellow-based). Eumelanin is, in the absence of colour modifer genes, black or dark brown (seal). Phaeomelanin is, in the absence of colour modifer genes, a yellowish/orangey colour known to cat fanciers as "red". Melanin is deposited on the hair shaft as the hair grows, but is not deposited at a constant rate. This results in the darker tips frequently seen on hairs. The Agouti protein affects the deposition of melanin in the growing hair and results in the banding effect (several bands of dark and light along the hair shaft). It causes alternating, distinct bands of eumelanin (black/brown) and phaeomelanin (red/yellow).

The mutant "Non-Agouti" form of the Agouti protein inhibits the banding effect and results in solid coloured hairs or hairs. The Tabby pattern genes inhibits the action of the Agouti gene in certain areas of the coat resulting in some agouti areas (ticked background colour) and some non-agouti areas (pattern). Sex-linked Red replaces the eumelanin in the growing hairs with phaeomelanin - the hairs are still ticked, but the bands of colour are light and dark red. Unlike eumelanin, phaeomelanin pigment is not greatly inhibited by the Non-Agouti protein hence red cats always show a tabby pattern.

Tortoiseshell cats have a patchwork effect; some areas of the coat have eumelanin while other areas have phaeomelanin. The eumelanistic areas are affected by tabby, non-agouti etc, but the phaeomelanin areas are not. As a result, the tabby pattern still shows up on the red areas regardless of whether the cat is a tortie or a tabby-tortie. A series of "rufous polygenes" affect the richness of the red colour - ranging from yellow-orange through to rich orange-red.

The B (black/brown) gene has a lightening effect on eumelanin. Depending on which of the B genes a cat has, the coat can be black/brown, chocolate or cinnamon. The D (dense/dilute) gene affects the density of pigment in the hair and affects both eumelanin and phaeomelanin. The effect is a washed out version of the original colour e.g. black becomes blue, red becomes cream. The Dm (dilute modifier) gene only affects the colour if the cats are already dilute (homozygous for the dilution gene). It "browns" or "caramelises" the diluted colour e.g. blue becomes caramel, cream becomes apricot.

 

Black/Brown Gene

Dilution

Dilute Modifier

Eumelanistic Colour

B-

D-

any

Brown/Black
(dilute modifier does not affect non-dilute colours)

B-

dd

dmdm

Blue

B-

dd

Dm-

Caramel (blue based caramel)

bb or bbl

D-

any

Chocolate

bb or bbl

dd

dmdm

Lilac

bb or bbl

dd

Dm-

Taupe (lilac based caramel)

blbl

D-

any

Cinnamon

blbl

dd

dmdm

Fawn

blbl

dd

Dm-

Fawn based Caramel

 

 

Red Gene

Dilution

Dilute Modifier

Phaeomelanistic Colour

O

D-

any

Red

O

dd

dmdm

Cream

O

dd

Dm-

Apricot

 

The C (full colour) gene comes in various flavours and causes different types of albino. Not all albinos are pure white! The C gene affects the intensity of melanin production. The normal (dominant form) is "full colour". The mutant forms affect the colour intensity and are temperature sensitive - the higher the temperature, the more effective they are. Cb is the Burmese factor and is only slightly temperature sensitive; it causes a slight lightening of black (eumelanin) to brown (sable) and of orange (phaeomelanin) to a yellow colour. Cs is the Siamese factor and is much more temperature sensitive; it has a much greater lightening effect than the Burmese factor causing greater contrast between the body colour and the points. Cats that have one copy of the Burmese factor and one copy of the Siamese factor show an intermediate effect known as Tonkinese. The most recessive form is c which is the rare pink-eyed albino totally lacking in pigment. Ca is the blue-eyed albino where there is a very small amount of pigment.

SCIENTIFIC SYMBOLS FOR GENES AND PHENOTYPES

+ means the wild type allele (when known); AD = autosomal dominant; AID = Autosomal Incompletely Dominant; AR = autosomal recessive; co-D = co-dominant; sex-linked = carried on X or Y chromosome. (Table below based on data from Online Mendelian Inheritance in Animals, OMIA. Sydney School of Veterinary Science, downloaded 3-May-2022, https://omia.org/ )

Trait (alleles)
OMIA Entry
Inherit-
ance
Mode
Phenotype
Gene
Gene Name
Mutation
Agouti/Non-agouti (A+, a)
000201-9685
AR
Agouti = Banded fur; non-agouti = solid
ASIP
Agouti-signalling protein
c.122_123delCA
Albinism/Colourpoint: oculocutaneous albinism type I (OCA1), TYR-related (C+, Cb, Cs, cm, c)
000202-9685
AR
Burmese, Mocha, Siamese colour pattern, full albino
TYR
Tyrosinase
cs = c.940G>A (Siamese)
cb = c.679G>T (Burmese)
c = c.939delc (complete albinism)
c = c.1204C>T (albinism)
c = c.975delC (albinism)
c.820_936delinsAATCTC (Mocha)
Albinism: Pink-Eyed, oculocutaneous, HPS5-related
002116-9685
AR
Donskoy breed "pink-eye," with associated light-brown skin, yellow irises and red-eye effect
Hermansky-Pudlak syndrome 5
HPS5
HPS5 Biogenesis Of Lysosomal Organelles Complex 2 Subunit 2
c.2571-1G>A (Donskoy)
Brachycephaly (Burmese)
001551-9685
Co-D
Burmese
ALX1
ALX homeobox 1
c.497_508del
Brown (B+, b, bl)
001249-9685
AR
Brown, light brown color variants
TYRP1
Tyrosinase related
protein
b = -5IVS6 (chocolate)
bl = c.298C>T (cinnamon)
Charcoal
002549-9685
AID
Bengal/Savannah charcoal pattern
ASIP
Agouti signalling protein
c.251A>G
c.302A>G
c.142T>C
c.41G>C
Chediak-Higashi Colour Dilution
000185-9685
AR
Persian, washed out smoky dilution with pale eyes.
LYST
lysosomal trafficking regulator
c.8347-2422_9548+1749dup
Colour Dilution (D+, d)
000206-9685
AR
Black to grey/blue, orange to cream
MLPH
Melanophilin
c.83delT
Cutaneous Asthenia
002165-9685
AD
Ehlers-Danlos syndrome, classic type, 1, hyper-elastic skin, winged cats
COL5A1
collagen, type V, alpha 1
c.3420del
Extension Gee (E+, e) – Amber, Russet, Copal
001199-9685
AR
Brown/red color variant
MC1R
melanocortin 1 receptor (alpha melanocyte stimulating hormone receptor)
c.250G>A (Amber, Norwegian Forest)
c.440_442del (Russet, Burmese)
c.640_669del (Copal/Carnelian, Kurilian Bobtail)
Ears: Curled Ears (K, k+)
000244-9685
AD
Backward curled ears
Unknown
Unknown
unknown
Ears: Folded Ears (Fd, fd+)
000319-9685
AID
Forward folded ears
TRPV4
transient receptor potential cation channel, subfamily V, member 4
c.1024G>T
Ears: Four Ears (Historic)
000320-9685
AR
Four ears with lethargy and small eyes (C Little, 1957)
Unknown
Unknown
unknown
Hairless: Hypotrichosis, Sphynx (Hr+, hr)
001583-9685
AR
Hypotrichosis, with whiskers short and curled. Hairlessness (Sphynx type)
KRT71
keratin 71, type II
c.816+1G>A
Hairless: Hypotrichosis, Lykoi, Hypotrichia and Roaning,
002229-9685
AR
Partial hairless and roaning, Lykoi breed
HRhairless
  c.1255_1256dup
c.1404+2delinsCAG
c.2112G>A
c.2243C>T
c.2593C>T
c.3389_3390insGACA
Hairless: Hypotrichosis, Birman
001949-9685
AR
Hypotrichosis, with short life expectancy (Birman)
FOXN1
forkhead box N1
c.1030_1033del
Hairless: Hypotrichosis, Don Sphynx
001866-9685
AID
Hairlessness, brush coat (Donskoy & Peterbald)
Unknown
Unknown
unknown
Inhibitor (I, i+)
001584-9685
Silver (I, i+)
001438-9685
AD
Absence of phaeomelanin, silver gene.
Unknown
Unknown
unknown
Longhair (L+, l)
000439-9685
AR
Long fur
FGF5
Fibroblast growth
factor 5
c.356_367insT (Ragdoll)
c.406C>T, (Norwegian Forest)
c.474delT, (Maine Coon, Ragdoll)
c.475A>C (Maine Coon)
c.577G>A (Maine Coon)
Tail: Japanese Bobtail (J, j+)
001987-9685
AD
Short, kinked tail
HES7
hes family bHLH transcription factor 7
c.5A>G
Tail: Manx, Short tail, Brachyury (M, m+)
000975-9685
AD
Absent/short tail
TBOX
T – box
c.1196del
c.1166del
c.995delT
c.[995_1011dup;1011_1014del]
Munchkin, Chondrodysplasia, UGDH-related
002541-9685
AD
Munchkin short limbs.
UGDH
UDP-glucose 6-dehydrogenase
g.174882895_174886198delinsN[108]
Orange (O, o+)
X linked
Eumelanin (black) to phaeomelanin (red)
Unknown
Unknown
unknown
Polydactyly (Pd, pd+)
000810-9685
AD
Extra toes
SHH
Sonic hedgehog
c.479A>G,
c.257G>C,
c.481A>T
Polydactyly (Pd, pd+)
000810-9685
AD
Extra toes
LMBR1
Limb Development Membrane Protein 1
 
Rex: Cornish/German (R+, r)
001684-9685
AR
Curly hair coat
(Cornish/German Type)
LPAR6
Lysophosphatidic acid
receptor 6
c.250_253delTTTG
Rex: Devon (Re+, re)
001581-9685
AR
Curly hair coat
(Devon Type)
KRT71
keratin 71, type II
c.1108-4_1184del, c.1184_1185insAGTTGGAG, c.1196insT
Rex: LaPerm Coat Type
000245-9685
AD
Curly hair coat
Unknown
Unknown
unknown
Rex: Selkirk (RS, rs+)
001712-9685
AD
Curly hair coat
(Selkirk type)
KRT71
keratin 71, type II
c.445-1G>C
Rex: Ural
002273-9685
? (all cats tested were homozygous)
Curly Coat
(Ural Rex)
LIPH
lipase, member H
c.477_483delinsC
Sunshine/Golden (Siberian)
002159-9685
AR
Sunshine (Siberian)
CORIN
corin, serine peptidase
c.2383C>T (see also "Wideband")
Tabby, Classic/Blotched (TM, tb)
001429-9685
AR
Blotched/classic pattern
TAQPEP
Transmembrane
aminopeptidase Q
S59X - c.176C>A (atypical swirl pattern)
T139N (classic)
D228N - c.682G>A (classic)
W841X - c.2522G>A (classic)
Tabby, Ticked (Ta, t)
001484-9685
AD
No tabby pattern, or residual markings at extremities and forehead
DKK4
dickkopf WNT signaling pathway inhibitor 4
c.53C>T (Abyssinian, Burmese, Maine Coon, Oriental shorthair)
c.188G>A (Abyssinian)
White (W, w+)
000209-9685
AD
Epistatic White. Loss of pigmentation
KIT
v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog
FERV1 LTR ins
White Gloves/Mitts (Birman) (G+, g)
001580-9685
AR
White feet
KIT
v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog
c.1035_1036delinsCA
White Spotting (S, s+)
000214-9685
Co-D
Bicolour (from “tuxedo” through to “van”, sometimes solid white (sometimes with temporary “kitten cap” marking)
KIT
v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog
7125ins FERV1 element
Wide-band
AR
Length of pheomelanin band in hair
CORIN
corin, serine peptidase
CORIN:C.839G>A - extreme-sunshine Siberian cats.
CORIN:C.2383C>T - sunshine Siberian cats.
CORIN:C.2425C>T copper/flaxen gold/akita British Shorthair/Longhair cats.
CORIN:C.1759C>T - golden tigers.

 

Further Reading:

Robinson's Genetics for Cat Breeders. This is currently in its 4th Edition (1999) and is the cat breeder's bible. However, further genes and a lot more mutations have been identified since it was published in 1999 and an updated version is eagerly awaited.

MESSYBEAST : BASIC GENETICS FOR BREEDERS & CAT LOVERS