American Fancy Rat & Mouse Association

Fancy Rat Genes, Alphabetical Name Listing

Marked Rats

For more rat genetics, see the AFRMA Rat Genetics book, specific articles listed with the various standards descriptions, and the articles on the Info Pages: Breeding – Colors/GeneticsRat Genetics, part 1, Rat Genetics, part 2, Rat Genetics, part 3. See also the Rat Biology article Why do some rats have white blazes and megacolon?
See the AFRMA Rat Color Standards book and the Standards pages for photos.

Go to Fancy Rat Genes, Alphabetical Name Listing for a complete list.

Go to Fancy Rat Genes, Agouti-based Colors,
Fancy Rat Genes, Black-based Colors, or
Fancy Rat Genes, Coats & Misc.

See also Fancy Rat Genes, Genetic Code Listing for breakdowns by genetic code.

Marked Rats
Albinocc (covers up the actual color/marking so can be either an agouti-based or black-based color; a.k.a. P.E. White)
Banded? (from Hooded stock)
Barebackhh or hhe or hHms or hhi?
BerkshireHh or hhe or hihi or hihn
Blazemany possible
Capped-Stripehreh; Hrehre (lethal)?
Collared? (usually from Dalmatian breedings) or Heh? or Hehi?
Down Underhdu? (dominant)
English IrishHh, or Hhi if no Hooded produced in 2 Irish breedings
EssexHro++ or Hro++H (color fading gene; has Berkshire markings but breeds as a Self)
Hoodedhh or hml
(Hm=Hooded Modifier; hms or hml—short or long)
IrishHh, or Hhi if no Hooded produced in 2 Irish breedings
Roan (Husky)? (recessive; roan gene lightens color with each moult till rat is nearly white; always in Berkshire or Berkshire Blaze markings)
Roan: Striped? (recessive; a.k.a. Banded Husky)
Snowflake? (small white spots belly and sides; a.k.a. stippeltjes in the Netherlands which means dots)
Tri-Merleheh Me?
Variegated? (2 Var. never produce Self or Hooded)
White: black-eyedhehe or any h
(marked selected for no spots; in either agouti-based or black-based color)
White: pink-eyedcc (albino; covers up the actual color/marking so can be either an agouti-based or black-based color) Note: extremely diluted P.E. Self colors or a P.E. Marked with all markings bred off can look like a P.E. White

C: Albino Locus (Burmese)+ (codes by Nichole Royer)
CFull color (no dilution)
ce+Extreme dilute
chAcromelanism (Himalayan/Siamese)
ci+Intense dilute
cAlbino (Pink-Eyed White)

Note: Many rat colors/varieties have not been studied by geneticists so codes are given by fancy rat genetics experts or are unknown

Note: Capital letter=dominant genes unless otherwise noted; lower case letter=recessive genes

“–” means that either the dominant or recessive allele could occupy that space without affecting the outcome

* = g or Me or Dal code by Nichole Royer

** = Cscs Fyfy code by Ann Storey, N.F.R.S.

+ = ce or ci code by Nichole Royer

++ = Hro code by Sheila Sowter, N.F.R.S.

? = genetics unknown

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Updated January 4, 2020