Congenital arthrogryposis: an inherited limb deformity in pedigree Suffolklambs

Thirty of 52 pedigree Suffolk lambs (58 per cent) were born with arthrogryp osis characterised by bilateral flexion rigidity of the metacarpophalangeal and carpal joints. The recent introduction of a breeding ram was identifie d as the only significant risk factor in the flock, and embryo transfer was used to test the hypothesis that the arthrogryposis was an inherited disor der associated with the introduction of this ram. Two adult ewes that had p reviously produced lambs with arthrogryposis by the ram and four of its aff ected daughters were available as donors, and 20 crossbred ewes were used a s recipients. Ten Suffolk-crossed ewes that had no known familial relations hip with the ram were also mated by the ram as controls and they produced 1 0 normal lambs. Following embryo transfer, 19 lambs were born, of which sev en were stillborn; arthrogryposis was evident in 10 of the 12 live lambs. A nalysis of the data suggested that in the population under study, arthrogry posis was inherited as an autosomal recessive condition.