Medical ConditionsCraniofacial & dental genetics: KBG syndrome
Medical ConditionsCraniofacial & dental genetics: KBG syndrome
KBG syndrome
Overview
Board takeaway: Recognize macrodontia with developmental and skeletal findings, then assess occlusion and the child’s medical and communication needs.
What causes KBG syndrome?
An ANKRD11 pathogenic variant or deletion involving the gene causes an autosomal dominant developmental disorder, often de novo. ANKRD11 contributes to chromatin regulation. KBG is named for the surname initials of the first described families.
Which systemic and facial findings occur in KBG syndrome?
Developmental and especially speech delay, variable intellectual disability, attention or autistic features, seizures or electroencephalographic abnormalities, feeding difficulty, reflux, hearing loss, and recurrent ear disease may occur. Skeletal features include short stature, delayed bone age, scoliosis, vertebral differences, and short fingers. Cardiac anomalies are possible. Facial clues include a triangular face, broad eyebrows, a prominent nasal bridge, and a long philtrum.
What oral findings distinguish KBG syndrome?
Macrodontia of the permanent maxillary central incisors is a major clue. Crowding, enamel defects, abnormal tooth shape or number, pits, talon cusps, and palatal abnormalities may occur. The tooth finding supports recognition in context; it is not a standalone molecular diagnosis.
How should dental care be planned for KBG syndrome?
Evaluate tooth dimensions, eruption, caries-prone grooves, and occlusal interference; refer for orthodontic assessment when needed. Use communication and behavioral supports matched to the child. Review seizures, hearing, cardiac findings, scoliosis, and airway history. Position comfortably and plan anesthesia from actual anatomy and medical status. Current ear or nasal problems may affect tolerance of nitrous oxide and require assessment.
What treatment and prognosis apply to KBG syndrome?
Multidisciplinary care addresses growth, feeding, development, seizures, hearing, and structural abnormalities. Many patients can have a normal lifespan; function and support requirements vary. Genetics confirms the cause when clinically indicated and supports family counseling.