<unk>  is a rare X-linked inherited disorder of brain development that causes both moderate to severe intellectual disability and problems with speech and movement.<unk> , which is named eponymously for William<unk> , Florence C.<unk> , and C. Nash<unk> , results from a mutation of the thyroid hormone transporter MCT8 (also referred to as SLC16A2). Consequently, thyroid hormones are unable to enter the nervous system, which depends on thyroid signaling for proper function and development.
Allan–Herndon–Dudley syndrome
Townes–Brocks syndrome
Fryns-Aftimos syndrome
Flynn–Aird syndrome
Kearns–Sayre syndrome
Grisel's syndrome
Dennie–Marfan syndrome
Lujan–Fryns syndrome