Lesch-Nyhan disease (LND) is caused by deficiency of hypoxanthine guanine 
phosphoribosyltransferase (HPRT). The aim of the present study is to 
characterize the molecular deficiency of a clinical diagnosed Chinese patient 
with attenuated variant of LND. The coding region and the intron-exon boundaries 
of HPRT1 gene were sequenced by standard methods, and HPRT activity was assayed 
by HPLC method. Structure analysis was performed to estimate the consequence of 
the mutant of HPRT1 gene. A new mutation c.245T>G (p.Ile82Ser) was identified in 
this patient, and heterozygous mutation was found in the patient's mother. The 
activity of HPRT in the patient was completely undetectable. Structure study 
indicates that the mutation of p.Ile82Ser may lead to loss of hydrophobic side 
chain and disrupt its normal conformation of HPRT protein. It is helpful for 
diagnosis of LND that sequencing analysis of HPRT1 gene is performed in male 
infant and juvenile with hyperuricaemia and neurologic dysfunction in Chinese.