What do sex-reversal syndrome, junctional epidermolysis bullosa, and autosomal trisomy have in common? They're all equine genetic diseases. But these conditions also have distinct differences that can help practitioners evaluate and diagnose suspect cases.

At the Equine Endocrine and Genetic Disorders Symposium, held Nov. 21 in Lexington, Ky., Teri Lear, PhD, equine genetics researcher at the University of Kentucky's Gluck Equine Research Center, delivered a presentation reviewing how practitioners can recognize genetic diseases in everyday practice.

Lear explained that there are two types of genetic disease: chromosome abnormalities and inherited disease. The former can include chromosome or DNA mutations (termed disorders of sex development, or DSD) or variations in chromosome structure or number. The latter includes diseases passed genetically from a parent to an offspring.

She reviewed how veterinarians can examine chromosomes and DNA (including the use of techniques called karoyping and fluorescence in situ hybridization, or FISH) before describing how these disorders appear in clinical practice