Complement gene mutations in children with C3 glomerulopathy: do they affect the response to mycophenolate mofetil?

Area of Science:

• Nephrology
• Genetics
• Complement System

Background:

• C3 glomerulopathy (C3G) is a complement-mediated kidney disease.
• Genetic testing aids in treatment planning and prognosis for C3G.
• Understanding genotype-phenotype correlations is crucial for pediatric C3G management.

Purpose of the Study:

• To investigate clinical phenotypes in pediatric C3G patients with and without complement-related gene mutations.
• To assess kidney survival rates in these pediatric C3G patient groups.
• To evaluate the response to mycophenolate mofetil (MMF) treatment based on genetic status.

Main Methods:

• Retrospective analysis of 60 pediatric C3G patients.
• Stratification into groups based on the presence or absence of complement-related gene mutations.
• Comparison of demographic, clinical-pathological, treatment, and outcome data; Kaplan-Meier analysis for kidney survival.

Main Results:

• 17 out of 60 patients had mutations, most commonly in the CFH gene.
• Mutation group had a higher mean age at diagnosis and more asymptomatic urinary abnormalities.
• No significant difference in MMF treatment response or kidney survival between groups; MMF showed no effect on progression.

Conclusions:

• The mutation group in pediatric C3G often presents with asymptomatic urinary abnormalities and later diagnosis.
• Despite genetic differences, MMF treatment response and kidney survival were similar between mutated and non-mutated C3G groups.
• This study highlights the importance of genotype in understanding C3G phenotypes but not treatment outcomes.