Novel GNB1 missense mutation in a patient with generalized dystonia, hypotonia, and intellectual disability

Recently, exome sequencing has extended our knowledge of genetic causes of developmental delay through identification of de novo, germline mutations in the guanine nucleotide-binding protein, beta 1 (GNB1) in 13 patients with neurodevelopmental disability and a wide range of additional symptoms and signs including hypotonia in 11 and seizures in 10 of the patients. Limb/arm dystonia was found in 2 patients.(1).