Paroxysmal hyperthermia, dysautonomia and rhabdomyolysis in a patient with Lesch–Nyhan syndrome

Lesch–Nyhan syndrome is an x‐linked genetic disorder of purine metabolism that results in the overproduction of uric acid and neurologic deficits manifesting as intellectual disability, dystonia, other movement disorders and self‐mutilation. We describe a 12‐year‐old patient with a history of Lesch–Nyhan syndrome, G6PD deficiency and central diabetes insipidus and multiple admissions for fever, acute kidney injury and transaminitis in the setting of rhabdomyolysis. The patient's temperature dysregulation and dysautonomia is likely attributable to abnormal neurotransmitter release, particularly that of dopamine, in the central nervous system. Our patient presented similarly to that of a patient with neuroleptic malignant syndrome (NMS), with symptoms including altered mental status, fever, dysautonomia and renal failure, and laboratory findings including elevated serum creatinine kinase, leukocytosis, transaminitis, hypernatremia and metabolic acidosis. Similar to NMS, disruption of dopamine neurotransmission results in dysregulated sympathetic activity and hyperthermia.