| 598114801 | The Study on the Clinical Phenotype and Function of HPRT1 Gene. | Guo M, etal., Child Neurol Open. 2022 Jul 19;9:2329048X221108821. doi: 10.1177/2329048X221108821. eCollection 2022 Jan-Dec. | Background: Lesch-Nyhan disease (LND) is a rare x-linked purine metabolic neurogenetic disease caused by enzyme hypoxanthine-guanine phosphoriribosyltransferase(HGprt) deficiency, also known as self-destructive appearance syndrome. A series of manifestations are caused by abnormal purine metabolism. The typical clinical manifestations are hyperuricemia, growth retardation, mental retardation, short stature, dance-like athetosis, aggressive behavior, and compulsive self-harm. Methods: We identified a point mutation c.151C > T (p. Arg51*) in a pedigree. We analyzed the clinical characteristics of children in a family, and obtained the blood of their parents and siblings for second-generation sequencing. At the same time, we also analyzed and compared the expression of HPRT1 gene and predicted the three-dimensional structure of the protein. And we analyzed the clinical manifestations caused by the defect of the HPRT1 gene. Results: The mutation led to the termination of transcription at the 51st arginine, resulting in the production of truncated protein, and the relative expression of HPRT1 gene in patients was significantly lower than other family members and 10 normal individuals. Conclusion: This mutation leads to the early termination of protein translation and the formation of a truncated HPRT protein, which affects the function of the protein and generates corresponding clinical manifestations. | 35875183 | 2022-12-01 |
| 13462064 | Analysis of the HPRT1 gene in 35 Italian Lesch-Nyhan families: 45 patients and 77 potential female carriers. | de Gemmis P, etal., Mutat Res. 2010 Oct 13;692(1-2):1-5. doi: 10.1016/j.mrfmmm.2010.07.003. Epub 2010 Jul 16. |
BACKGROUND: Lesch-Nyhan (LND) disease is an inborn error of purine metabolism which results from deficiency of the activity of hypoxanthine-guanine phosphoribosyltransferase (HPRT). In the classical form of the disease the activity of the enzyme is completely deficient and the patient has cognitive impairment, spasticity, dystonia and self-injurious behaviour, as well as elevated concentrations of uric acid in blood and urine that leads to consequences such as nephropathy, urinary tract calculi and tophaceous gout. There are disease variants without self-injurious behaviour. In these cases neurological manifestations may vary widely. The HPRT1 gene is located on the X chromosome in position Xq26-27.2, and mutations have been found in quite a large number of patients.
OBJECTIVE: Documenting our experience with the diagnosis of LND in 45 Italian patients from 35 nonrelated families and 77 females at risk of being carriers of the condition.
DESIGN: Internal review.
SETTING: An institute devoted to the investigation and care of patients with rare diseases.
RESULTS: In 94% of the LND families gDNA sequencing of the patients was informative while in 6% a cDNA study was required. For the carrier females gDNA sequencing was informative in 71% of the families, 23% required qPCR studies and 6% required segregation studies combined with enzymatic activity testing. Classical cDNA studies proved to be unreliable in carrier females as there is a significant risk of failure to detect the mutated allele. Four novel HPRT1 mutations were found: c.145C>T (p.Leu49Phe), c.112C>T (p.Pro38Ser), c.89_96dup8 (p.Glu33Argfs) and c.506dupC (p.Arg170Thrfs).
CONCLUSION: In the diagnosis of LND it is very important to consider all the possible alterations of the HPRT1 gene when searching for mutations especially if no affected male is available. Biochemical assessment of the enzymatic activity of HPRT in an affected male is the ideal starting point for molecular analysis of the gene. | 20638392 | 2010-10-13 |
| 13463104 | Hypoxanthine guanine phosphoribosyltransferase (HPRT) deficiencies: HPRT1 mutations in new Japanese families and PRPP concentration. | Yamada Y, etal., Nucleosides Nucleotides Nucleic Acids. 2014;33(4-6):218-22. doi: 10.1080/15257770.2013.865743. | Mutation of hypoxanthine guanine phosphoribosyltransferase (HPRT) gives rise to Lesch-Nyhan syndrome, which is characterized by hyperuricemia, severe motor disability, and self-injurious behavior, or HPRT-related gout with hyperuricemia. Four mutations were detected in two Lesch-Nyhan families and t wo families with partial deficiency since our last report. A new mutation of G to TT (c.456delGinsTT) resulting in a frameshift (p.Q152Hfs*3) in exon 3 has been identified in one Lesch-Nyhan family. In the other Lesch-Nyhan family, a new point mutation in intron 7 (c.532+5G>T) causing splicing error (exon 7 excluded, p.L163Cfs*4) was detected. In the two partial deficiency cases with hyperuricemia, two missense mutations of p.D20V (c.59A>T) and p.H60R (c.179A>G) were found. An increase of erythrocyte PRPP concentration was observed in the respective phenotypes and seems to be correlated with disease severity. | 24940672 | 2014-12-01 |
