Family History of Alport Syndrome with Spectrum of Chronic Kidney Disease, Dialysis and Transplantation

ABSTRACT

Introduction: Alport syndrome should be considered in the differential diagnosis of patients with persistent microhematuria. Electron microscopic examination of renal tissue remains the most widely available and applied means for diagnosing AS. The presence of diffuse thickening and multilamellation of the GBM predicts a progressive nephropathy, regardless of family history. Unfortunately, ultrastructural information alone does not establish the mode of transmission in a particular family. Method(s) 18 years-old male patient was followed in the clinic due to persistent microscopic haematuria and proteinuria. Family history is significant for one brother in his early 20s, who started to have the presentation early in life and his initial biopsy showed thin basement membrane disease. The brother subsequently progressed to renal failure and a repeat biopsy confirmed the presence of Alport syndrome. Another brother had end-stage renal disease and underwent renal transplantation. The patient status was revised, and genetic studies confirmed the presence of an autosomal recessive type of Alport syndrome involving collagen for A3 chain COL4A3. His kidney function remained stable initially with an estimated GFR of approximately 90 mL/min/1.73 m2. The most recent eGFR is around 70 ml/min/1.73 m2. His proteinuria disappeared once Losartan 25 mg was added to Ramipril 5 mg. His blood pressure has been on target. Creatinine increased to 147 micromol/L and he was diagnosed as having acute kidney injury on chronic renal disease which was obvious post covid infection, then back to baseline. Current proteinuria 3 g/g Cr on Angiotensin receptor blockers. BP 110/70, all other systemic examination is unremarkable. No hearing or visual abnormalities. Result(s) The initial renal manifestations in early childhood include asymptomatic-persistent microscopic hematuria and rarely gross hematuria. At the onset, the serum creatinine and blood pressure are normal. Over time, proteinuria, hypertension, and progressive renal insufficiency develop. ESRD usually occurs between the ages of 16 and 35 years and rarely can occur between 45 and 60 years. Renal biopsy findings of thinning and multilaminar splitting of the glomerular capillary basement membrane seen on electron microscopic examination are pathognomonic. In 2013, an expert panel issued guidelines recommending genetic testing as the gold standard for the diagnosis of Alport syndrome. Currently, a skin biopsy using commercially available monoclonal antibody against the type IV collagen alpha-5 chain (COL4A5). If the protein is clearly absent in a suspected male, a diagnosis of Alport syndrome can be made without further testing. Conclusion(s) Males with X-linked AS due to a deletion mutation of the alpha 5 chain of type IV collagen usually progress to ESRD by the second or third decade of life. Likewise, patients with autosomal recessive AS due to mutations affecting alpha 3 or 4 chains of type IV collagen tend to progress to ESRD by age 30. Autosomal-dominant AS with heterozygous mutations of COL4A3 or COL4A4 usually has a slower progression of CKD. Treatment is blood pressure control with RAAS inhibitors where clinically appropriate. Cyclosporine may be helpful in some patients with stage I and II CKD with significant proteinuria. Caution using calcineurin inhibitors is indicated in all patients with more advanced CKD stages due to potential nephrotoxicity. No conflict of interestCopyright © 2023