Novel PAX2 gene variant related renal dysfunction with morning glory syndrome: a case report

초록

Paired box 2 ( PAX2)-related disorder is an autosomal dominant disorder associated with kidney and eye abnormalities and can result in end stage renal disease. We report a case of renal dysfunction with morning glory syndrome caused by a novel PAX2 gene variant. An 8-year-old boy visited the nephrology clinic with proteinuria discovered during a school examination. His laboratory findings showed proteinuria (834 mg/day, 31 mg/m2/hr) and decreased renal function. His plasma levels of creatinine and Cystatin-C were increased (1.33 mg/dL and 1.44 mg/L, respectively). Renal Doppler ultrasonography showed both small size and increased echogenicity of both kidneys. He underwent a kidney biopsy to determine the cause of proteinuria and decreased renal function. His kidney biopsy showed that abnormal glomerular basement membrane structure with diffuse mild mesangial proliferation, suggesting the possibility of Alport syndrome. In past medical history, he was previously diagnosed with congenital optic disc coloboma, but did not follow up after his age of 3 years. During this school physical examination, he was also recommended for an ophthalmologic examination due to poor eyesight, and was diagnosed with morning glory syndrome. He underwent genetic test for Alport syndrome and PAX2 gene to find out the cause of the eye and kidney abnormalities, and as a result, heterozygous novel non-sense variant of the PAX2 gene (NM_003990.4, p.Gln258*) was found. This variant was categorized as likely-pathogenic according to the standards and guidelines of the American College of Medical Genetics and Genomics. Genetic testing is required for accurate diagnosis and prognosis when patients with unknown cause of proteinuria and decreased renal function are accompanied by ocular symptoms.