Lesch-Nyhan disease (LND) is associated with a marked decrease in hypoxanthine-guanine phosphoribosyltransferase (HPRT) activity.


Inheritance: X-linked recessive


Genetic locus: Xq26-q27


Clinical findings:

(1) neurologic disability

(1a) marked delay in motor development with hypotonia and spasticity (which may not be detected until several months of age)

(1b) extrapyramidal dysfunction with dystonia, choreoathetosis and/or ballismus

(1c) pyramidal dysfunction with hyperreflexia and extensor plantar response (positive Babinski sign)

(1d) dysarthria

(2) cognitive disability (may be normal)

(3) behavioral problems with self-mutilation

(3a) biting of tongue, lips, fingers or other body parts

(3b) head banging or snapping

(3c) eye poking

(3d) activities damaging to fingers and/or extremities

(4) gouty arthritis

(5) uric acid and/or hypoxanthine nephrolithiasis, with urinary tract infection and renal insufficiency

(6) growth retardation

(7) dysphagia and emesis, with risk of aspiration

(8) fevers due to infection and/or joint inflammation and/or respiratory infection


The patient may have a sibling with similar findings.


Laboratory findings:

(1) hyperuricemia and hyperuricosuria, with elevation in the urine urate to creatinine ratio

(2) markedly reduced HPRT activity (< 1.5% residual activity)

(3) megaloblastic anemia

(4) biochemical evidence of renal insufficiency


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