DNA TEST FOR NEURONAL CEROID LIPOFUSCINOSIS IN TIBETAN TERRIERS
Neuronal Ceroid Lipofuscinosis (NCL) is a neurodegenerative genetic disorder of Tibetan Terriers.
Breeders will be sent results identifying their dog as belonging to one of three categories:
CLEAR: The dog has 2 copies of the normal gene and will neither develop neuronal ceroid lipofuscinosis, nor pass a neuronal ceroid lipofuscinosis gene to its offspring.
CARRIER: The dog has one copy of the normal gene and one copy of the mutant gene that causes neuronal ceroid lipofuscinosis. It will not develop neuronal ceroid lipofuscinosis but will, if bred from, pass on the mutant gene to, on average, 50% of its offspring.
AFFECTED: The dog has 2 copies of the mutant gene that causes neuronal ceroid lipofuscinosis and will develop the disease.
Inheritance
NCL in Tibetan Terriers is an autosomal recessive disorder. Crossing the three genotypes - clear, carrier or affected - will produce the following litters:
Parents Litters
clear x clear all clear
clear x carrier approximately 50% clear 50% carriers
clear x affected all carriers
carrier x carrier approximately 25% clear, 50% carriers 25% affected
carrier x affected approximately 50% clear 50% affecteds
affected x affected all affecteds