Year: 2026
Type: review
Abstract: Monocarboxylate transporter 8 (MCT8) deficiency, also known as Allan–Herndon–Dudley syndrome, is a rare, severely debilitating, and life-limiting genetic disorder caused by variants in the SLC16A2gene that render the MCT8 thyroid hormone transporter partially or completely dysfunctional. MCT8 is highly expressed throughout the body, including the brain. Its deficiency disrupts thyroid hormone homeostasis and is associated with two distinct concomitant clinical presentations: persistent peripheral thyrotoxicosis resulting from elevated serum levels of triiodothyronine and neurodevelopmental impairment arising from low thyroid hormone levels in the brain. The disorder severely impacts quality of life and reduces life expectancy to a median of 35 years due to a range of clinical sequelae, with approximately 30% of affected individuals dying during childhood. Recognition and treatment of thyrotoxicosis are crucial to prevent associated symptoms and long-term sequelae.
Language: English
Subfield: Endocrinology, Diabetes and Metabolism
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7126139856