Birk-Barel Intellectual Disability Dimorphism and KCNK9 Imprinting Syndrome: Craniofacial Surgery Considerations for an Exceedingly Rare Syndrome.

Birk-Barel intellectual disability dimorphism syndrome, also referred to as KCNK9 imprinting syndrome, is an exceedingly rare condition described in under 20 cases that presents with intellectual disability, hypotonia, scoliosis, dysphonia, dysphagia, and craniofacial dysmorphic features. The condition follows an autosomal dominant pattern of inheritance in the maternally expressed KCNK9 gene on chromosome 8. Due to the complexity of presentation, patients with Birk-Barel syndrome are optimally managed by a multidisciplinary team including a craniofacial surgeon. Previously described craniofacial dysmorphic features include micrognathia, cleft palate, dolichocephaly, broad nasal tip, and broad philtrum, among others. Here the authors describe a genetically confirmed case that has been managed in our institution's multidisciplinary cleft and craniofacial clinic. The authors aim to discuss Birk-Barel syndrome for a surgical and craniofacial audience with considerations for operative management in the context of a multidisciplinary team.