[Thyroid hormone resistance may course hypotonia in infancy]

Area of Science:

• Genetics
• Endocrinology
• Neurology

Background:

• Allan Herndon Dudley's syndrome (AHDS) is an X-linked disorder characterized by intellectual disability and hypotonia.
• It results from mutations in the MCT8 gene, which encodes a thyroid hormone transporter.

Observation:

• Neonatal screening using thyroid-stimulating hormone (TSH) may not detect AHDS.
• Boys presenting with hypotonia and/or developmental delay require specific thyroid hormone level assessment.

Findings:

• A case report details a four-and-a-half-month-old boy diagnosed with AHDS.
• The diagnosis was confirmed by identifying a typical thyroid profile (elevated T3, low-normal T4, normal/elevated TSH) and DNA analysis.

Implications:

• This highlights the importance of a comprehensive thyroid profile for diagnosing AHDS in at-risk infants.
• Early identification enables prompt management and support for affected individuals.