Variability in phenotype induced by the podocin variant R229Q plus a single pathogenic mutation
PJ Phelan, G Hall, D Wigfall, J Foreman… - Clinical Kidney …, 2015 - academic.oup.com
Clinical Kidney Journal, 2015•academic.oup.com
Background Mutations in podocin (NPHS2) are the most common cause of childhood onset
autosomal recessive steroid-resistant nephrotic syndrome (SRNS). The disease is
characterized by early-onset proteinuria, resistance to immunosuppressive therapy and
rapid progression to end-stage renal disease. Compound heterozygous changes involving
the podocin variant R229Q combined with another pathogenic mutation have been
associated with a mild phenotype with disease onset often in adulthood. Methods We …
autosomal recessive steroid-resistant nephrotic syndrome (SRNS). The disease is
characterized by early-onset proteinuria, resistance to immunosuppressive therapy and
rapid progression to end-stage renal disease. Compound heterozygous changes involving
the podocin variant R229Q combined with another pathogenic mutation have been
associated with a mild phenotype with disease onset often in adulthood. Methods We …
Background
Mutations in podocin (NPHS2) are the most common cause of childhood onset autosomal recessive steroid-resistant nephrotic syndrome (SRNS). The disease is characterized by early-onset proteinuria, resistance to immunosuppressive therapy and rapid progression to end-stage renal disease. Compound heterozygous changes involving the podocin variant R229Q combined with another pathogenic mutation have been associated with a mild phenotype with disease onset often in adulthood.
Methods
We screened 19 families with early-onset SRNS for mutations in NPHS2 and WT1 and identified four disease-causing mutations (three in NPHS2 and one in WT1) prior to planned whole-exome sequencing.
Results
We describe two families with three individuals presenting in childhood who are compound heterozygous for R229Q and one other pathogenic NPHS2 mutation, either L327F or A297V. One child presented at age 4 years (A297V plus R229Q) and the other two at age 13 (L327F plus R229Q), one with steadily deteriorating renal function.
Conclusions
These cases highlight the phenotypic variability associated with the NPHS2 R229Q variant plus pathogenic mutation. Individuals may present with early aggressive disease.
Oxford University Press