👤 Stanislav Kmoch

Autosomal dominant tubulointerstitial kidney disease (ADTKD) is an increasingly recognized rare condition with 3 primary characteristics: autosomal dominant inheritance, bland urinary sediment (absence of hematuria and proteinuria), and chronic kidney disease (CKD) leading to kidney failure (need for kidney replacement therapy or kidney transplantation) between 20 and 80 years of age, with a mean age of kidney failure of approximately 45 years. Pathogenic variants in UMOD, MUC1, REN, and APOA4 have been identified as causative in ADTKD families. Prior to 2000, ADTKD was only diagnosed clinically and had been described in fewer than 50 families. However, with the advent of genetic testing and a better understanding of this condition, ADTKD is being increasingly recognized and is the third most common monogenic cause of kidney failure. The purpose of this review is to provide an understanding of the clinical characteristics of ADTKD and its subtypes with a practical approach to diagnosis and management for clinical nephrologists. Show less

Sporadic cases of apolipoprotein A-IV medullary amyloidosis have been reported. Here we describe five families found to have autosomal dominant medullary amyloidosis due to two different pathogenic APOA4 variants. A large family with autosomal dominant chronic kidney disease (CKD) and bland urinary sediment underwent whole genome sequencing with identification of a chr11:116692578 G>C (hg19) variant encoding the missense mutation p.L66V of the ApoA4 protein. We identified two other distantly related families from our registry with the same variant and two other distantly related families with a chr11:116693454 C>T (hg19) variant encoding the missense mutation p.D33N. Both mutations are unique to affected families, evolutionarily conserved and predicted to expand the amyloidogenic hotspot in the ApoA4 structure. Clinically affected individuals suffered from CKD with a bland urinary sediment and a mean age for kidney failure of 64.5 years. Genotyping identified 48 genetically affected individuals; 44 individuals had an estimated glomerular filtration rate (eGFR) under 60 ml/min/1.73 m Show less