Partial defect of iodide trapping mechanism in two siblings with congenital goiter and hypothyroidism.

Abstract

ABSTRACT Two siblings, a 23-yr-old woman and a 34-yr-old man, with congenital goiter and hypothyroidism were referred to the thyroid clinic for evaluation. They were on thyroid extract since early childhood and attained normal growth but were mentally retarded. Inbreedings were noted in the family pedigree but no cases of goiter were reported. The BMR was low for both patients and PBI was 1.0 μg and 2.2 μg/100 ml, respectively. T4-I was 1.0 μg and 1.8 μg/100 ml. The perchlorate test was negative. The TRC test was repeatedly negative. The RAI uptake was 3.5% and 6.0% at 24 hr with no response to TSH. Plasma chromatography of iodinated compounds disclosed only iodide and iodoproteins. Traces of T3 + T4 were present in one sairrole. Plasma TSH was very high in both patients. The resting mixed saliva/plasma ratio at 2, 4 and 6 hr after a iv dose of 131I were, respectively, 7.2 and 5.9, 8.7 and 5.9, 7.9 and 6.7 for HCR, and JFCR (normal controls: 27.7–64.3). The gastric juice/plasma ratio was 5.2 and 5.0 seven...