Single, Double and Triple Blockade of RAAS in Alport Syndrome: Different Tools to Freeze the Evolution of the Disease

Case report: A novel compound heterozygous variant in the COL4A3 gene was identified in a patient with autosomal recessive Alport syndrome

Alport syndrome (AS), a hereditary kidney disease with a high risk for renal failure, is attributed to pathogenic variants in genes COL4A3, COL4A4, and COL4A5 that encode type IV collagen. Next-generation sequencing (NGS) is increasingly applied to the diagnosis of AS, but complex genotype-phenotype correlation, that is, identifying the significance of variants, is still a huge clinical challenge. In this study, we reported the case of a 27-year-old Chinese woman with a family history of hematuria and proteinuria. Notably, the proband is the only one in her family with renal insufficiency. NGS was performed in this family, and it was revealed that the proband was a compound heterozygote for two variants in the COL4A3 gene: c.2990G>A inherited from her father and c.4981C>T inherited from her mother. We modeled the spatial structure of the corresponding protein and assumed that structural abnormalities led to the breakdown of type IV collagen networks, a major component of the glomerular basement membrane. Thus, the proband was diagnosed with autosomal recessive AS, characterized by severe defects of the glomerular basement membrane. Hence, the proband showed a loss of renal function. This case presentation emphasizes the importance of NGS for AS diagnosis and introduces a novel genotype of AS.

Inherited causes of combined vision and hearing loss: clinical features and molecular genetics

Combined vision and hearing loss, also known as dual sensory impairment, can occur in several genetic conditions, including ciliopathies such as Usher and Bardet-Biedl syndrome, mitochondrial DNA disorders and systemic diseases, such as CHARGE, Stickler, Waardenburg, Alport and Alstrom syndrome. The retinal phenotype may point to the diagnosis of such disorders. Herein, we aim to provide a comprehensive review of the molecular genetics and clinical features of the most common non-chromosomal inherited disorders to cause dual sensory impairment.

Renin angiotensin aldosterone inhibitors in the treatment of proteinuria in children with congenital anomalies of the kidney and urinary tract: more evidence needed

INTRODUCTION

Congenital anomalies of the kidney and urinary tract (CAKUT) can be associated with proteinuria, possibly leading to a decline in kidney function. The aim of this review is to evaluate evidence on the efficacy of renin-angiotensin-aldosterone system inhibitors (RAASi) in children affected by CAKUT with proteinuria or chronic kidney disease (CKD).

AREAS COVERED

We conducted a bibliographic search between 1 December 2022 and 20 February 2023, including randomized controlled trials, case-control studies, observational studies, meta-analyses, and systematic reviews dealing with the efficacy of RAASi in reducing proteinuria and slowing the decline of kidney function in children.

EXPERT OPINION

RAASi are effective in reducing proteinuria and slowing CKD progression in many renal conditions; however, the efficacy of these drugs in patients affected by CAKUT with proteinuria is still unknown. While waiting for more evidence, when facing a child with CAKUT with isolated proteinuria or with proteinuria and CKD, a 6-12-month trial with RAASi with gradual increase to the maximal tolerated dose should be considered. If no improvement of proteinuria is obtained, the RAASi should be discontinued.