Abstract 81: A case report of elevated TSH, elevated T3 and low T4 levels and mutation in SLCA5A gene: A diagnostic dilemma

Background: Iodide transport defect (ITD) is one of the causes of thyroid dyshormonogenesis. It is an uncommon disorder which is mediated by NIS mutations. They present with hypothyroidism and goitre due to the absence of active transport of iodide into the thyroid gland. The clinical presentation of patients with ITD due to different mutations of NIS gene has been described: including T354P, G395R, Q267E, and G543E mutations. Case Report: A 10-year-old boy born out of non – consanguineous marriage, with no antenatal, postnatal complications presented with history of goitre for 7 years. The child had a history of ADHD, average scholastic performance, and history of weight gain of 4-5 kilograms over past 2 months. Mother was diagnosed to have hypothyroidism during pregnancy. His Thyroid profile showed FT4 – 0.413 ng/dL, FT3 – 6.06 pg/mL, TSH – 12.75 mIU/mL and USG neck showed mild thyromegaly. A genetic analysis was done which revealed a homozygous mutation on Exon 7 in SLC5A5 gene. Child was started on Levothyroxine supplementation. Conclusion: The clinical picture is suggestive of hypothyroidism with elevated free T3 levels. This genetic mutation needs to be followed up in the global data base to ascertain its significance in future.