Lesch–Nyhan syndrome

Overview

Board takeaway: Protect bitten tissues with a coordinated self-injury plan; weigh irreversible extraction against feasible alternatives and review aspiration and renal risk.

Compulsive lip and tongue biting can cause severe injury and requires coordinated protective care.

How does Lesch–Nyhan syndrome affect dental management?

• Team plan: Stepwise, least-invasive-first plan with neurology, caregivers and the medical team
• Protection: Behavioral strategies and stress reduction; protective devices (mouthguards, lip bumpers, bite blocks) when tolerated
• Specialist option: Botulinum toxin has been described in specialist reports; it is not an established routine dental protocol and requires specialist selection and follow-up
• Consider extraction: persistent, severe tissue injury despite a feasible protective plan. Discuss selective or more extensive extraction with the multidisciplinary team and family.
• Before deciding: specify the injuring teeth, alternatives tried, expected functional losses, and continuing risk after new teeth erupt. Extraction is irreversible and individualized.
• Before treatment or anesthesia: review medications; assess positioning, swallowing, and renal function.
• Why these matter: dystonia affects positioning, dysphagia increases aspiration risk, and uric acid nephropathy can impair renal function.

Exam pearl

What is Lesch–Nyhan syndrome?

An X-linked HPRT1-related purine metabolism disorder causing excess uric acid, motor dysfunction, and characteristic self-injurious behavior.

What are the main systemic features of Lesch–Nyhan syndrome?

• Genetics: HPRT1 deficiency (hypoxanthine-guanine phosphoribosyltransferase); X-linked recessive, affects boys
• Uric acid overproduction: gout, kidney stones, orange "sand" crystals in the diaper
• Neurologic features: Severe dystonia and motor disability, cognitive impairment, dysarthria, dysphagia
• Self-injury: Compulsive self-injury usually begins around age 2–3, often with primary tooth eruption, despite intact pain sensation
• Treatment limit: Allopurinol controls uric acid but not the neurobehavioral features

What oral findings occur in Lesch–Nyhan syndrome?

• Self-mutilation of lips, tongue, buccal mucosa and fingers with tissue loss and scarring
• Ulceration, infection and bleeding of bitten tissues
• Caregiver-dependent oral hygiene; aspiration risk from dysphagia

Sources

• Supplemental systemic features: MedlinePlus Genetics: lesch nyhan syndrome
• Supplemental study guide: Pediatric Dental Study Guide: Lesch Nyhan Syndrome
• Management of Dental Patients with Special Health Care Needs
• Behavior Guidance for the Pediatric Dental Patient
• Management of the Developing Dentition and Occlusion in Pediatric Dentistry