The American Angus Association currently recognizes the following genetic conditions:
AM – Arthrogryposis Multiplex D2 – PRKG2 Gene Mutation for Dwarfism HG – Horn Gene
CA – Contractural Arachnodactyly DM – Double Muscling HI – Heterochromia Irides
DD – Developmental Duplication DW – Dwarfism OS – Osteopetrosis
M1 – nt821 mutation for Double Muscling RD – Red Gene SN – Syndactyly
NH – Neuropathic Hydrocephalus WT – Wild Type Color Gene
The following single letter descriptors appearing after a genetic condition code shall have the following meaning:
P – Refers to a “potential” carrier based on an ancestor known to carry that specific mutation.
F – Refers to an animal tested for one or more genetic conditions and determined to be “free” of that specific mutation.
C – Refers to an animal tested for one or more genetic conditions and determined to be a “carrier” of that specific mutation.
A – Refers to an animal tested for one or more genetic conditions and determined to be a carrier of two copies of that specific mutation. It may or may not exhibit the phenotype associated with that genetic condition.
The following letter designations describe cases in which there is more than one genetic condition present:
XF – Free of more than 1 genetic condition
XC – Carrier of more than 1 genetic condition
XA – Affected of more than 1 genetic condition
RTF – Recessive Trait Free (Produced 35 or more calves from daughters without a genetic defect)
NOTE: The genetic condition codes and descriptors reflect the available, reported genetic condition status of the animal. The Association does not warrant or guarantee that any animal is free of all genetic conditions, whether coded or not coded.

AVOIDANCE OF MATING CARRIER ANIMALS WITH THE SAME GENETIC CONDITION IS AN ESSENTIAL COMPONENT OF MANAGING THE INCIDENCE OF GENETIC CONDITIONS, AS IS THE STRATEGIC USE OF DNA TESTING.

For more information, click here to consult the Breeder’s Reference Guide.