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Lesch-Nyhan syndrome; hypoxanthine-guanine phosphoribosyltransferase (HGPRT) deficiency
Etiology:
- deficiency in HPRT1 results in purine excess
Epidemiology: rare
Pathology:
-> urate crystals may form in joints, kidneys, central nervous system, & other tissues
Genetics:
1) X-linked recessive disease
2) associated with defects in HPRT1
Clinical manifestations:
1) self-mutilating behaviors such as biting of lips & fingers &/or head banging
2) symptoms usually occur 3-6 months of age
3) urate crystals often appear as orange-colored crystal-like deposits (orange sand) in diapers
4) nephrolithiasis
5) hematuria
6) arthritis (gout)
7) dysphagia
8) vomiting
9) renal insufficiency
10) irritability
11) uncontrolled aggressive and/or compulsive actions
12) hypotonia
13) spasms
14) athetosis
15) chorea
16) facial grimacing
17) moderate mental retardation common
Laboratory:
1) increased levels of uric acid in serum & urine
2) complete blood count (CBC) (monitor for megaloblastic anemia)
Complications:
-> megaloblastic anemia may occur
Management:
1) symptomatic
2) allopurinol to reduce serum & urinary uric acid
3) kidney stones may be treated with lithotripsy
4) no standard treatment for neurological symptoms
-> some symptoms may be relieved with carbidopa/levodopa, diazepam, phenobarbital, or haloperidol
5) prognosis is poor
a) no treatment for the neurological defects
b) uric acid deposition in tissues causes agonizing episodes of self-mutilation & may result in severe retardation &, ultimately, death
General
enzyme deficiency
syndrome
X-linked disease
Properties
DEFICIENCY: hypoxanthine guanine phosphoribosyl transferase
Database Correlations
OMIM correlations
References
- OMIM 308000
- NINDS Lesch-Nyhan Syndrome Information Page
https://www.ninds.nih.gov/Disorders/All-Disorders/Lesch-Nyhan-Syndrome-Information-Page