Nephrotic syndrome and adrenal insufficiency caused by a variant in SGPL1

Abstract

Little is known about the molecular pathogenesis of congenital nephrotic syndrome in association with primary adrenal insufficiency. Most recently, three groups found concurrently the underlying genetic defect in the gene sphingosine-1-phosphate lyase 1 ( SGPL1) and called the disease nephrotic syndrome type 14 (NPHS14). In this report we have performed whole-exome sequencing and identified a new homozygous variant in SGPL1, p.Arg340Trp, in a girl with nephrotic syndrome and Addison's disease. Her brother died previously with the same phenotype and hyperpigmentation of the skin. We reviewed the reported cases and concluded that NPHS14 is a clinically recognizable syndrome. The discovery of this syndrome may contribute to the diagnosis and description of additional patients who could benefit from treatment, genetic counseling and screening for related comorbidities. Until now, patients with congenital nephrotic syndrome associated with primary adrenal insufficiency have been treated as having two different diseases; however, the treatment for patients with NPHS14 should be unique, possibly targeting the sphingolipid metabolism.