Internal Medicine

0521779407-17 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:19

Purine and Pyrimidine Disorders 1255

General Measures

■referral to biochemical genetics center

■adjust or avoid nephrotoxic medications (HPRT, APRT, XDH defs.,

PRPS superactivity)

■high fluid intake (HPRT, APRT, XDH, UMPS defs., PRPS superactivity)

■treat intercurrent infection (ADA, PNP defs.)

■irradiated blood products (ADA, PNP defs.)

■hearing testing (PRPS superactivity)

specific therapy

■indicated for all symptomatic patients

Treatment Options

■HPRT deficiency: allopurinol, physical restraint, teeth removal,

mouth guard, behavioral therapy for self-injurious behavior, phar-

macotherapy (e.g., risperidone, gabapentin)

■APRT deficiency: allopurinol, low purine diet, avoid alkali, renal

transplantation

■PRPS superactivity: allopurinol

■XDH deficiency: low purine diet

■ADA deficiency: bone marrow transplantation, polyethylene glycol

(PEG) ADA, gene therapy in clinical trials

■UMPS deficiency: uridine supplementation

Side Effects & Contraindications

■allopurinol may cause xanthine stone formation in HPRT deficiency

■decrease dose of allopurinol in renal failure

■severe graft-versus-host disease may occur in ADA, PNP deficiencies

if non-irradiated blood products used

■patients with DHPD and DHPA deficiencies should not be given 5-

fluorouracil (extremely toxic)

follow-up

Routine

■close monitoring of renal function (HPRT, APRT, XDH defs., PRPS

superactivity)

■periodic hearing testing (PRPS superactivity)

■genetic counseling

complications and prognosis

■HPRT deficiency: death secondary to renal failure, aspiration pneu-

monia in adolescence