Dystonia: A novel sign of the Smith-Magenis syndrome – A three-case report

Abstract

The Smith-Magenis syndrome (SMS) is a rare genetic disorder caused by a microdeletion in the 17p11.2. region or a pathogenic variant of the RAI1 (retinoic acid-induced), which is located in the 17p11.2 area. In most cases, SMS is caused by a heterozygous de novo deletion. Sometimes inherited mutations of the RAI1 are described, suggesting an autosomal dominant inheritance. There is a broad spectrum of symptoms, including distinctive facial features, skeletal malformations, varying intellectual disability, speech, motor skills delay, sleep disturbances, and self-injurious or attention-seeking behaviors. Despite an extensive literature review, the manifestation of dystonia remains absent from documented cases. Dystonia represents a notable clinical symptom, the recognition of which may prompt the initiation of genetic testing and facilitate precise diagnostic assessment.