Congenital Primary Hypothyroidism with the Homozygous Nonsense Mutation P.K1374* in the Thyroglobulin Gene and a Normal-sized Thyroid Gland on Levothyroxine Replacement

Intern Med. 2019 Sep 15;58(18):2669-2673. doi: 10.2169/internalmedicine.1163-18. Epub 2019 Jun 7.

Abstract

Thyroglobulin (TG) gene mutations cause thyroid dyshormonogenesis, which is typically associated with a congenital goiter. We herein report the case of a 64-year-old man with congenital primary hypothyroidism who had a normal-sized thyroid gland on levothyroxine replacement. He had short stature (-3.1 standard deviations) and mild intellectual impairment. Thyroid autoantibodies were all negative, and the serum TG levels were undetectable. Eventually, he was found to have the novel homozygous nonsense mutation p.K1374* in the TG gene. The possibility of TG mutation should be considered for patients with congenital primary hypothyroidism and a very low serum TG level, regardless of the thyroid size.

Keywords: congenital hypothyroidism; gene mutation; goiter; thyroglobulin.

Publication types

  • Case Reports

MeSH terms

  • Codon, Nonsense
  • Congenital Hypothyroidism / diagnosis
  • Congenital Hypothyroidism / drug therapy
  • Congenital Hypothyroidism / genetics*
  • Homozygote
  • Humans
  • Male
  • Middle Aged
  • Mutation
  • Organ Size
  • Thyroglobulin / genetics*
  • Thyroid Function Tests
  • Thyroid Gland / diagnostic imaging*
  • Thyroid Gland / pathology
  • Thyroxine / therapeutic use

Substances

  • Codon, Nonsense
  • Thyroglobulin
  • Thyroxine