Subclinical hyperthyroidism due to a thyrotropin receptor (TSHR) gene mutation (S505R)

Area of Science:

• Endocrinology
• Genetics
• Pediatrics

Background:

• Congenital non-autoimmune hyperthyroidism is a rare condition.
• Activating germline mutations in the thyrotropin receptor (TSHR) gene are known causes.

Observation:

• A 6-month-old infant presented with weight loss and subclinical hyperthyroidism.
• The infant's condition was non-autoimmune.

Findings:

• Direct sequencing of the TSHR gene identified a heterozygous point mutation (S505R).
• This mutation was confirmed as the molecular defect causing the infant's hyperthyroidism.

Implications:

• The study suggests that TSHR gene mutations should be considered in cases of subclinical non-autoimmune hyperthyroidism, not just severe forms.
• This expands the diagnostic criteria for genetic testing in pediatric thyroid disorders.