[Genetic analysis of two children with sporadic neurofibromatosis type 1 complicated with nephrotic syndrome].

OBJECTIVE
To explore the genetic basis for two children with sporadic neurofibromatosis type 1 (NF1) complicated with nephrotic syndrome (NS).


METHODS
Clinical data of the children were collected. Both children were subjected to high-throughput sequencing, and candidate variants were verified by Sanger sequencing.


RESULTS
Both children had café-au-lait macules, subaxillary freckle and Lisch nodules. Child 1 also had congenital tibiofibular pseudarthrosis on the left side. Genetic testing revealed that child 1 has harbored a heterozygous c.844C>T variant in the exon 8 of the NF1 gene, whilst child 2 has harbored a heterozygous c.1246C>T variant in the exon 11 of the NF1 gene. Both children were diagnosed with NF1 and have developed pronounced proteinuria, hypoalbuminemia, hypercholesterolemia and pitting edema at the ages of 3 and 10, respectively. Renal biopsy of child 2 has revealed minimal change nephropathy, and the diagnosis of nephrotic syndrome was established. Child 1 was treated with glucocorticoid, and child 2 was treated with glucocorticoid in combination with mycophenolate mofetil. The NS was relieved with no recurrence during 1 year's follow-up.


CONCLUSION
NF1 combined with NS is rare in the clinical settings. The prognosis of children with NF1 combined with minimal change nephropathy is relatively good. Detection of NF1 gene variant can facilitate early identification and diagnosis of NF1.