A1 Refereed original research article in a scientific journal

Very-Early Onset Autoimmune Hypothyroidism: A Report of Two Cases with STAT3 Gain-Of-Function Variant




AuthorsRavi, Rowmika; Niskanen, Anita; Reeve, Mary Pat; Makkonen, Kristiina; Niinikoski, Harri; Toppari, Jorma; Kero, Jukka

PublisherBioscientifica

Publication year2025

Journal: European thyroid journal

Article numberETJ-25-0260

ISSN2235-0640

eISSN2235-0802

DOIhttps://doi.org/10.1530/ETJ-25-0260

Publication's open availability at the time of reportingOpen Access

Publication channel's open availability Open Access publication channel

Web address https://doi.org/10.1530/etj-25-0260

Self-archived copy’s web addresshttps://research.utu.fi/converis/portal/detail/Publication/505607672


Abstract

Autoimmune hypothyroidism occurs rarely before three years of age. Two siblings were diagnosed with autoimmune hypothyroidism at age five and 16 months, presenting with classic symptoms of hypothyroidism, abnormal thyroid function tests (TSH 200 and 660 mU/L; reference 0.73-8.4 mU/L; Free T4 5.9 and <1.3 pmol/L; reference 11.9-25.6 pmol/L), and high thyroid peroxidase antibody levels. Thyroxine medication alleviated their symptoms. Apart from mild infections, the siblings exhibited no other major disorders. Whole exome sequencing identified a pathogenic STAT3 gain-of-function variant, most commonly associated with infantile-onset multi-organ autoimmune disorder. Genetic testing for early-onset hypothyroidism may reveal specific etiologies, impacting follow-up and treatment.


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Funding information in the publication
This study was supported by the Finnish Paediatric Society (Grant number 190001), the Sigrid Jusélius Foundation (Grant number 115-1956-26), and the Novo Nordisk Foundation (Grant number 0078329).


Last updated on 19/12/2025 09:43:12 AM