Hereditary kidney diseases: New perspectives through next-generation sequencing analysis

Background and aim: Hereditary kidney diseases are characterized by a specific phenotypic homology while differing in prognosis and follow-up. The genetic analysis may not be conclusive, thereby limiting a better understanding of these types of kidney diseases. The next-generation sequencing (NGS) technique allows for the simultaneous analysis of multiple genes, which, although more time consuming, enables new pathogenetic mutations to be recognized, and encourages research and diagnosis of hereditary kidney diseases. The aim of the present article is to provide a comprehensive review of the literature regarding the isolated finding of fetal hyperechoic kidneys.  Methods: A systematic review was conducted in MEDLINE including articles evaluating the genetic approach to fetal hyperechoic kidneys. The PRISMA-P recommendations were used to guide this review. Results: A genetic etiology was identified in 48% of cases. Of these, 38% were autosomal recessive polycystic kidney disease (ARPKD), 29% were autosomal dominant polycystic kidney disease (ADPKD), and 22% were HNF1B-related autosomal dominant tubulointerstitial kidney disease. Genetic analysis was performed using karyotype, chromosomal microarray, and specific sequencing for PKD1-PKD2 or PKHD1. Only 4 studies reported NGS analysis permitting complex diagnoses. Conclusions: The genetic approach using the NGS technique is still underused despite allowing a faster etiological classification without an increase in diagnostic costs. Since genetic etiology is responsible for 48% of fetal hyperechoic kidneys, the application of NGS techniques should be implemented in order to encourage research in this not-yet-widely-known field of study.