Step-by-Step Guide
How to Read a Frenchie DNA Test
Decode every section of your DNA report — from color genes to health risks — so you can breed and buy with total confidence.
Try the DNA CalculatorUnderstanding Your DNA Report
When your French Bulldog's DNA test results arrive, they typically contain two major sections: a Color & Coat report and a Health Screening report. Each gene is listed by its locus name (like B-Locus, D-Locus, E-Locus) followed by a genotype — two letters separated by a slash.
The letters represent alleles — different versions of the same gene. Capital letters (B, D, E) are dominant alleles. Lowercase letters (b, d, e) are recessive alleles. A dog receives one allele from each parent, which is why every genotype has two letters.
Below is a complete breakdown of every locus you'll see on a standard Frenchie DNA panel, what each genotype means visually, and how it affects breeding outcomes.
Color Genes Decoded
Every color locus on your DNA report controls a specific pigment or pattern. Here is what each result means for your dog's appearance.
B-Locus
Testable ChocolateControls: Brown eumelanin pigment
B / BNo chocolate. Black pigment in all eumelanin areas.
Visual: Black, Blue, Fawn, Brindle
B / bCarrier. Looks normal but can pass chocolate to 50% of offspring.
Visual: Looks like B/B
b / bChocolate expressed. Brown pigment replaces black.
Visual: Chocolate, Lilac, Isabella
D-Locus
Blue / DiluteControls: Pigment intensity dilution
D / DNo dilute. Full-strength pigment in all areas.
Visual: Black, Chocolate, Fawn
D / dCarrier. Looks normal but can pass dilute to 50% of offspring.
Visual: Looks like D/D
d / dDilute expressed. All pigment is lightened.
Visual: Blue (on black), Lilac (on chocolate)
E-Locus
Cream / MaskControls: Eumelanin production in coat
E / EFull pigment production. No cream possible from this dog alone.
Visual: Fawn, Brindle, Black-based colors
E / eCarrier. Looks normal but can pass cream to 50% of offspring.
Visual: Looks like E/E
e / eCream expressed. No dark pigment in the coat at all.
Visual: Solid cream or off-white
K-Locus
Brindle / Dominant BlackControls: Pattern suppression or expression
K / KDominant black. Brindle is fully suppressed.
Visual: Solid color, no brindle pattern
K / kCarrier. Looks solid but can allow brindle in offspring.
Visual: Looks like K/K
k / kBrindle allowed. A-locus pattern is visible.
Visual: Brindle pattern shows through
A-Locus
Fawn / Sable / TricolorControls: Base coat pattern type
Ay / AyFawn/sable. Red-yellow base with dark tips.
Visual: Fawn Frenchie
Ay / atFawn carrying tricolor. Can produce tan-pointed puppies.
Visual: Looks fawn
at / atTricolor expressed. Tan points on dark body.
Visual: Black & tan or tricolor
S-Locus
Piebald / White MarkingsControls: White spotting and coverage
S / SNo piebald. Minimal to no white markings.
Visual: Solid colored body
S / sModerate white. White chest, blaze, or socks.
Visual: Some white markings
s / sPiebald expressed. Large white patches across body.
Visual: Pied Frenchie
Health Genes Decoded
Health results use the same genotype format. Here is how to read every health locus on your Frenchie DNA panel.
DM (Degenerative Myelopathy)
Gene: SOD1 — Progressive spinal paralysis in senior dogs
N / NNo risk. Cannot produce affected puppies.
N / DMHealthy, but passes DM to 50% of offspring.
DM / DMWill develop paralysis. Never breed.
HUU (Hyperuricosuria)
Gene: SLC2A9 — Bladder and kidney stones from excess uric acid
N / NNo risk. Safe to breed to any partner.
N / HUUHealthy, but passes HUU to 50% of offspring.
HUU / HUUWill form stones. Requires lifelong management.
JHC (Juvenile Hereditary Cataracts)
Gene: HSP70 — Clouded vision and blindness in young dogs
N / NNo risk. Vision will develop normally.
N / JHCHealthy eyes, but passes JHC to 50% of offspring.
JHC / JHCWill develop cataracts. Never breed.
CMR1 (Canine Multifocal Retinopathy)
Gene: BEST1 — Retinal lesions that impair vision
N / NHealthy retina. No vision risk.
N / CMR1Healthy vision, but passes CMR1 to 50% of offspring.
CMR1 / CMR1Retinal lesions will develop. Never breed.
What to Do With Your Results
Once you understand every genotype, here is the exact next step for breeders and buyers.
Run the DNA Calculator
Enter both parents' full genotypes to see exact probabilities for every color and health outcome in your litter. It takes 60 seconds.
Open CalculatorScreen Every Pairing
Before you breed, verify that no two carriers of the same health gene are paired together. Our calculator flags risky combinations automatically.
Check PairingsShare Results With Buyers
Give puppy buyers a copy of the parents' DNA reports and the calculator results. Transparency builds trust and justifies pricing.
Learn MoreRe-Test Through a Second Lab
If a result surprises you, confirm it with a second DNA testing lab. Embark, Animal Genetics, and DDC all test the same loci with high accuracy.
Compare LabsTurn Results Into Predictions
Now that you can read your DNA report, put those genotypes to work. Our calculator predicts litter outcomes across all 18 loci instantly.
Launch the DNA CalculatorFrequently Asked Questions
What does B/B mean on a Frenchie DNA test?
B/B means your dog has two dominant copies of the B-locus gene. It will not produce chocolate pigment and cannot pass chocolate to its offspring. B/b means it carries one chocolate gene (hidden), and b/b means it expresses chocolate coat color.
How do I know if my Frenchie carries the blue (dilute) gene?
Look at the D-locus result. D/D means no dilute gene. D/d means your dog carries one copy of the dilute gene but looks normal — it can produce blue or lilac puppies when bred to another carrier. d/d means your dog expresses the dilute gene and will appear blue (on black base) or lilac (on chocolate base).
What is the difference between carrier and affected on health results?
Carrier (N/DM, N/HUU, etc.) means your dog has one normal copy and one mutated copy. The dog is healthy but can pass the mutation to offspring. Affected (DM/DM, HUU/HUU, etc.) means two mutated copies — the dog will either develop the condition or already shows symptoms. Never breed two carriers of the same health gene together.
Why does my cream Frenchie show e/e on the E-locus?
e/e is the recessive genotype at the E-locus. It means your dog cannot produce black pigment in its coat, which is why it appears cream or off-white. E/e dogs look normal but carry cream. E/E dogs have full pigment and cannot produce cream puppies unless bred to an e/e partner.
How do I use my DNA results for breeding decisions?
Enter both parents' genotypes into our DNA Calculator. The tool instantly shows the probability of every coat color and health outcome for your litter. Use this to avoid risky health pairings and to predict which colors your litter can produce.
Can two visually black Frenchies produce a blue puppy?
Yes — if both parents carry the recessive d allele at the D-locus (genotype D/d). Each puppy has a 25% chance of being d/d (blue). Our DNA Calculator shows these odds precisely for every locus.