Lesch-Nyhan Disease and Its Variants: Phenotypic and Mutation Spectrum of Hypoxanthine-Guanine Phosphoribosyltransferase Deficiency in Argentine Patients

Abstract Hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency is a disorder of purine metabolism responsible for Lesch-Nyhan Disease (LND) and its variants, HPRT-related hyperuricemia with neurologic dysfunction (HND) and HPRT-related hyperuricemia (HRH). The objective of this study was to characterize a cohort of Argentine patients with HPRT deficiency diagnosed in a single center. Results: Twenty nine patients were studied, including 12 LND, 15 HND and 2 HRH. The average onset age was 0.64 years for LND with motor delay as the main manifestation, 8.84 years for HND and 2.5 years for HRH; nephrological manifestations predominated as presenting features in these variants. The average diagnosis age was 3.58 years for LND, 17.21 years for HND and 2.5 years for HRH. Clinical heterogeneity was more evident in HND, even in members of the same family. All patients presented hyperuricemia and no detectable HPRT activity in erythrocyte lysate. The molecular study allowed to identify 9 different mutations in HPRT1 gene from 24 patients (11 independent pedigrees) and to establish genotype-phenotype correlation. In conclusion, this study describes the genotypic/phenotypic spectrum of HPRT deficiency in Argentine patients and highlights the need to increase awareness about the suspicion of these diseases, especially the LND variants with high clinical heterogeneity.

A Case of Lesch-Nyhan Disease Manifesting Gouty Arthritis without Self-mutilation / 대한신장학회지

Lesch-Nyhan disease is a very rare X-linked recessive disorder characterized by mental retardation, spasticity resembling cerebral palsy, choreoathetosis, self-mutilation and hyperuricemia. Self-mutilative behavior is a hallmark of the disease. The underlying defect is a deficiency of hypoxanthine-guanine phosphoribosyltransferase (HPRT). We report on a fourteen-year-old boy, who manifested gouty arthritis and mild renal insufficiency with Lesch-Nyhan disease, lacking self-mutilative behavior in spite of undetectable HPRT activity. Though there were several reports about some cases of Lesch-Nyhan disease in the past Korean literature, the cases were classic forms with definite neurological manifestation. As far as we know, this is the first case of Lesch-Nyhan disease without self-mutilation in Korea.

Cloning, Expression and Immunization of The Hypoxanthine-guanine Phosphoribosyltransferase for Schistosoma japonicum Chinese Strain / 生物化学与生物物理进展

A 1 270 bp full-length cDNA fragment was obtained from the Schistosoma japonicum (Chinese strain) adult cDNA library after the '3' and 5' ends of the incomplete expression sequence tag (EST) of hypoxanthine-guanine phosphoribosyltransferase of Schistosoma japonicum (SjHGPRT) were amplified by the anchored PCR with 2 pairs of primer that were designed according to the published incomplete SjHGPRT EST and the sequence of multiclone sites of library λgt1 1 vector. Sequence analysis indicated that this fragment, with an identity of 82% to hypoxanthine-guanine phosphoribosyltransferase ofSchistosoma mansoni (SmHGPRT), contained a complete open reading frame(ORF). The deduced amino acid sequence showed 83% identity to that of SmHGPRT. This fragment was cloned into the prokaryotic expression vector pQE30, and subsequently sequenced and expressed in Escherichia coli. SDS-PAGE revealed that M of the recombinant protein was about 28 ku. Western-blot analysis showed that the recombinant protein was recognized by the polyclonal antisera from rabbits immunized with Schistosoma japonicum adult worm antigen. Mice vaccinated with recombinant protein revealed significant worm burden, liver eggs per gram (LEPG), fecal eggs per gram (FEPG) and intrauterine eggs of the female worms reduction percentage, compared with the controls. Taken together, the SjHGPRT full-length cDNA can be cloned and expressed in E. coli as a recombinant protein that elicited immunity against the challenge infection with Schistosoma japonicum, indicating its potential as a partia1 protection vaccine candidate.

Cloning,Expression and Immunization of The Hypoxanthine-guanine Phosphoribosyltransferase for Schistosoma japonicum Chinese Strain / 生物化学与生物物理进展

A 1 270 bp full-length cDNA fragment was obtained from the Schistosoma japonicum (Chinese strain) adult cDNA library after the 3′ and 5′ ends of the incomplete expression sequence tag (EST) of hypoxanthine-guanine phosphoribosyltransferase of Schistosoma japonicum (SjHGPRT) were amplified by the anchored PCR with 2 pairs of primer that were designed according to the published incomplete SjHGPRT EST and the sequence of multiclone sites of library ?gt11 vector. Sequence analysis indicated that this fragment, with an identity of 82% to hypoxanthine-guanine phosphoribosyltransferase of Schistosoma mansoni (SmHGPRT), contained a complete open reading frame(ORF). The deduced amino acid sequence showed 83% identity to that of SmHGPRT. This fragment was cloned into the prokaryotic expression vector pQE30, and subsequently sequenced and expressed in Escherichia coli. SDS-PAGE revealed that M of the recombinant protein was about 28 ku. Western-blot analysis showed that the recombinant protein was recognized by the polyclonal antisera from rabbits immunized with Schistosoma japonicum adult worm antigen. Mice vaccinated with recombinant protein revealed significant worm burden, liver eggs per gram (LEPG), fecal eggs per gram (FEPG) and intrauterine eggs of the female worms reduction percentage, compared with the controls. Taken together, the SjHGPRT full-length cDNA can be cloned and expressed in E.coli as a recombinant protein that elicited immunity against the challenge infection with Schistosoma japonicum, indicating its potential as a partial protection vaccine candidate.

Three Cases of Lesch-Nyhan Syndrome: Cases report

Lesch-Nyhan syndrome is a rare X-linked recessive metabolic disorder characterized by developmental delay, hyperuricemia, choreoathetosis, spasticity, mental retardation, and compulsive self-injurious behavior. This disorder results from a complete deficiency of the purine salvage enzyme, hypoxanthine-guanine phosphoribosyltransferase (HGPRT). This syndrome is often misdiagnosed to cerebral palsy and clinical manifestations are usually related to the degree of enzyme deficiency. Complete HGPRT deficiency presents with severe specific neurologic manifestation and nephrolithiasis leading to fatal kidney damage. This report highlighted the importance of clinical awareness leading to early diagnosis and therapy for prevention of the self mutilation and renal failure, even if we couldn't inhibit the progression of neuro-psychotic symptoms.

Cloning and expression of the gene encoding hypoxanthine-guanine phosphoribosyltransferase of Schistosoma japonicum / 中国血吸虫病防治杂志

Objective To perform the cloning of the gene encoding Schistosoma japonicum Chinese-strain hypoxanthine-guanine phosphoribosyltransferase(HGPRT)and its expression in Escherichia coli.MethodsA couple of primers were designed with the BamHI restriction endonuclease site introduced in forward primer and SalI in reverse primer.Total RNA was isolated from adult worms of S.japonicum Chinese-strain(Anhui-strain,Sjc-A)and the SjcHGPRT gene was amplified by reverse transcriptase-polymerase chain reaction(RT-PCR).The PCR product and the prokaryotic expression vector pET28a were digested by both restriction endonucleases BamHI and SalI.The target DNA fragments were purified and cloned properly into pET28a.After identification by en-donucleases digestion,PCR and sequencing,the recombinant plasmid pET28a-SjcHG PRT was transformed into competent E.coli BL21 and expressed in the presence of IPTG.Results pET28a-SjHGPRT was sequenced and shown to be 99% and 83% identical in deduced amino acid sequence to that of S.japonicum Chinese-strain(Hunan-strain,Sjc-H)and S.mansoni HGPRT,respectively.The results of SDS-PAGE and Western blot revealed that the molecular weight of expressed protein was around 30 kDa and could be recognized by anti-His-G-HPR antibody and sera from mice and human with schistosomasis japonica.Conclusion The recombinant plasmid containing SjcHGPRT cDNA is successfully constructed and its expression protein(reSjcHGPRT)is also successfully purified.