Steroid-resistant nephrotic syndrome in infants caused by a novel compound heterozygous mutation of the NUP93 A CARE case report

Rationale: Steroid-resistant nephrotic syndrome (SRNS) is a special kidney disease. SRNS is characterized by steroid-resistant, clinical variability, and genetic heterogeneity. Patients with SRNS often may eventually need renal transplantation. Patient concerns: A 10-month-old Chinese male infant presented with oliguria, renal dysfunction, hypertension, and anemia. Diagnoses: Combined with clinical manifestations, laboratory testing and sequencing results, the patient was diagnosed as SRNS. Interventions: Combined intravenous methylprednisolone and cefoperazone sulbactam did not improve the patient's condition. Thus, SRNS associated with hereditary nephrotic syndrome was strongly suspected. Genetic testing for hereditary renal disease of the patient revealed 2 novel heterozygous mutations in the Nucleoporin 93 (NUP93) gene, which were predicted pathogenic and harmful by bioinformatic softwares of SIFT, PolyPhen_2 and REVEL. Outcomes: As general physical health deterioration and renal dysfunction, the patient died of a severe infection. Lessons: The novel NUP93 heterozygous mutations identified in the current study broadened the genetic spectrum of SRNS and further deepened our insight into pathogenic mutations of NUP93 to improve disease diagnosis.