Molecular Analysis of the AGXT Gene Detected a Missense and Pathogenic Variant Associated with Primary Hyperoxaluria Type 1; a Case Study

Abstract

Background Primary Hyperoxaluria Type 1 (PH1) is an autosomal recessive genetic disorder triggered by a mutation in the alanine glyoxylate aminotransferase (AGXT) gene. Early detection of PH1 is a pre-requisite as it causes End Stage Renal Disease (ESRD) in most patients in the early stages. An eleven years old girl with a history of kidney disease and stones and with phenotypic characteristics of PH1 was brought to the laboratory. A c.568G>A mutation in AGXT gene, which is responsible for PH1, is found in a homozygous condition. Further study revealed the detection of the mutation in heterozygous form in both the parents. This study provides insight to generate more reliable genetic markers for the early detection of PH1 in a family or a population. This can lead to better and earlier treatment strategies. Case Presentation This study aimed to detect the AGXT gene mutationswhich are responsible for primary hyperoxaluriain the patient.AGXT gene screening was done in her parents for identifying the root cause and zygosity of the mutation. The AGXT gene on chromosome2q37.3was amplified via polymerase chain reaction and sequenced by Sanger sequencing. Molecular modeling and genetic change analysis was performed by using in-silico parameters. Conclusion The sequence analysis revealed the presence of a missense and pathogenic variant in the homozygous condition in the AGXT gene exon 5;c.568G>A with protein change p. Gly190Arg in the patient. Parental screening showed that the patient received one allele from her father and the other from her mother. A liver transplant followed by a kidney transplant was carried out in the patient with 6 months difference. The study emphasized that as theb mutation p.Gly190Arg is reported as a cause of PH1, this mutation can be considered an early diagnostic marker for PH1.