Allan-Herndon-Dudley syndrome

The Allan-Herndon-Dudley syndrome is characterized by mental retardation (XL-MR) and neuromuscular involvement with muscle hypoplasia and hypotension.

Hypotonia develops further into spasticity, which may include hyperreflexia, contactors, Babinski's signs, and clonus. In addition, there are hypoplastic muscles, difficulty controlling headaches, general muscle weakness, intellectual deficits and motor developmental delays. In addition, the patients have prominent facial features, including an open mouth, tent-shaped upper lip, ptosis, abnormal ears, soft tissue thickening of the nose and ears, and erect earlobes. Long, thin, everted legs, funnel chest, and scoliosis are also typical symptoms. Mutations (chain termination, deletions, nonsense and missense mutations) in the SLC16A2 gene are assumed to be the cause of the syndrome. This code for a specific transporter (MCT8) of the T3 thyroid hormone. The disease is inherited as an x-linked recessive trait. In the 25 families with 89 patients, only men were affected. The patients have a limited life expectancy, but there have already been patients who have survived for up to 60 years. Diseased people can not live autonomously.