Clinical Course and Images of Four Familial Cases of Allan-Herndon-Dudley Syndrome With a Novel Monocarboxylate Transporter 8 Gene Mutation

BACKGROUND: Allan-Herndon-Dudley syndrome, an X-linked condition characterized by severe intellectual disability, dysarthria, athetoid movements, muscle hypoplasia, and spastic paraplegia, is associated with defects in the monocarboxylate transporter 8 gene (MCT8). The long-term prognosis of Allan-Herndon-Dudley syndrome remains uncertain. PATIENTS: We describe the clinical features and course of four adults in a family with Allan-Herndon-Dudley syndrome with athetoid type cerebral palsy. RESULTS: We identified an MCT8 gene mutation in this family. Two of the four affected family members died at 32 and 24 years of age. CONCLUSIONS: Individuals with Allan-Herndon-Dudley syndrome are at increased risk for recurrent infection, such as aspiration pneumonia. These individuals require careful management with consideration for this increased risk of recurrent infection.