The Study on the Clinical Phenotype and Function of HPRT1 Gene.

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.