Congential hypothyroidism generally is divided into sporadic (nongoitrous) and goitrous types.1.2 The non-endemic goitrous variety usually has been associated with enzymatic defects inherited as autosomal recessive traits.3 Persons with sporadic hypothyroidism do not have goiters and may not have demonstrable thyroid tissue. The aplastic or hypoplastic type of primary hypothyroidism has been found to occur in 63% of infants indentified in newborn screening programs.4 This condition has not been considered to be genetically transmitted, since rarely is more than one family member affected. Previous case reports in the literature have not demonstrated successfully that hereditary nongoitrous hypothyroidism can occur, but recently we have seen two siblings with congenital hypothyroidism in whom no thyroid tissue could be detected by throid imaging.
Report ofCases.—Case 1.—A boy who was 6 years 5 months old was referred to the Texas Children's Hospital, Houston, for evaluation of possible hypothyroidism. Gestation