Isolated TSH deficiency

Isolated TSH deficiency is a rare autosomal recessive disease, that cause congenital hypothyroidism. Patients were found to have homozygous splice site mutation in the TSH beta subunit gene. They show symptoms of severe mental and growth retardation that can be prevented by early administration of exogenous thyroid hormone. Levothyroxine replacement therapy is the treatment of choice. Concomitant corticotropin deficiency should be excluded prior to starting therapy in order to avoid an adrenal crisis.