Other names: CDDY/IVDD, CDPA, Hansen's Type I IVDD, Intervertebral Disc Disease with or without chondrodysplasia

Affected genes:
Chr12-FGF4 (CDDY/IVDD)
Chr18-FGF4 (CDPA)

Inheritance:
Chondrodysplasia (CDPA): Autosomal dominant
Chondrodystrophy (CDDY): Autosomal dominant

Mutation:
CanFam 3.1 CDDY/IVDD: Chr12:33710168-33710178: 3209 bp insert with duplication (AAGTCAGACAGAG)
CDPA: Chr18:20443725-20443726: ~5 kb insert

OMIA link:
000157-9615: CDDY-IVDD (Chr12-FGF4)
002542-9615: CDPA (Chr18-FGF4)

Appropriate breeds for testing: 
For Chr12-FGF4 (CDDY/IVDD):
American Cocker Spaniel, Basset Hound, Beagle, Bichon frisé, Cardigan Welsh Corgi, Chesapeake Bay Retriever, Chihuahua, Coton de Tulear, Dachshund, English Springer Spaniel, French Bulldog, Nova Scotia Duck Tolling retriever, Miniature American Shepherd

Chr18-FGF4 (CPDA):
Basset Hound, Cairn Terrier, Cardigan Welsh Corgi, Dachshund, Dandie Dinmont Terrier, Lancashire heeler, Norwich Terrier, Pekingese, Pembroke Welsh Corgi, Petit Basset Griffon Vendéen, Shih-Tzu, Skye Terrier, Swedish Vallhund, Tibetan Spaniel, West Highland Terrier.

Dogs carrying both mutations show a more drastic reduction in leg length.