|COLE, JOHN - Former ARS Employee|
|WOLFE, CARI - American Jersey Cattle Association|
Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: 4/2/2021
Publication Date: 6/28/2021
Citation: Al-Khudhair, A.S., Null, D.J., Cole, J.B., Wolfe, C.W., Van Raden, P.M. 2021. Inheritance of a mutation causing neuropathy with splayed forelimbs in Jersey cattle [abstract]. Journal of Dairy Science. 104(Suppl. 1):77–78(abstr. 199).
Technical Abstract: A new undesirable genetic factor, known as Neuropathy with Splayed Forelimbs (JNS), has been identified recently in the Jersey breed. Calves affected with JNS are unable to stand on splayed forelimbs that exhibit significant extensor rigidity and/or excessive lateral abduction at birth. Affected calves are generally alert at birth but exhibit neurologic symptoms including spasticity of head and neck and convulsive behavior. Other symptoms reported include dislocated shoulders, congenital craniofacial anomalies, and degenerative myelopathy. Inheritance of the undesirable genetic factor was determined from a study of 16 affected calves reported by Jersey breeders across the country. Their pedigrees all traced on both paternal and maternal sides to a common ancestor born in 1995. Genotypes revealed that JNS is attributable to a specific haplotype on Bos taurus autosome (BTA) 6, and about 6% of the genotyped Jersey population are now carriers of the haplotype. The region of shared homozygosity was further examined by sequencing, revealing missense variant rs1116058914 at base 60,158,901 of the ARS-UCD1.2 reference map as the most concordant with the genetic condition and most likely cause. The single base substitution (G/A) is in the coding region of the last exon of the ubiquitin C-terminal hydrolase L1 (UCHL1) gene that is conserved across species. Mutations in humans and gene knockouts in mice cause similar recessive symptoms and muscular degeneration. Since December 2020, carrier status is tracked with a haplotype and reported for all 303,087 genotyped Jersey animals. With random mating, about 300 affected calves per year would result from the 370,000 U.S. Jersey cows in DHI. Selection and mating programs can reduce the number affected using either the haplotype status or a direct gene test in the future. Breeders should report calf abnormalities to their breed association to help discover new defects such as JNS.