Hereditary congenital goiter with thyroglobulin deficiency in a breed of goats.

Hereditary congenital goiter occurring in an inbred breed of goats is reported. The goitrous goats were severely hypothyroid. Thyroglobulin-related antigens could only be detected by radioimmunoassay in amounts of 0.03% of the total protein concentration in the 105,000 x g supernate of the goitrous gland, which corresponded with 8 microgram soluble thyroglobulin-related antigens/g tissue. After treatment with digitonin, 4 microgram thyroglobulin-related antigens/g tissue could be extracted from the sediment. This means that the gland contained about 12 microgram thyroglobulin-related antigens/g tissue (normal about 100 mg/g). However, no thyroglobulin (19S) could be detected by ultracentrifugation experiments, immunodiffusion, or immunoelectrophoresis. Iodinated proteins with sedimentation constants of 3-9S were found. Among these iodinated macromolecular compounds, iodinated "albumin" and some non-hydrolysable iodinated material was found. These last mentioned components were also found in the blood, indicating a leakage from the gland. As described for comparable cases, these results indicate a defect in thyroglobulin synthesis or its regulation.