[Clinical phenotype analysis of 6 cases of TTC21B gene related nephronophthisis]

Area of Science:

• Pediatric Nephrology
• Clinical Genetics
• Rare Diseases

Background:

• Nephronophthisis is a rare genetic kidney disease.
• TTC21B gene mutations are implicated in certain forms of nephronophthisis.
• Early diagnosis is crucial for managing pediatric kidney diseases.

Purpose of the Study:

• To describe the clinical features of children with TTC21B-related nephronophthisis.
• To aid in the early clinical diagnosis of this rare condition.
• To provide insights into the disease progression and associated complications.

Main Methods:

• Retrospective analysis of clinical data from 6 children diagnosed with TTC21B-related nephronophthisis.
• Data collected included general condition, clinical manifestations, and laboratory tests.
• Genetic testing confirmed TTC21B gene variations in all patients.

Main Results:

• All 6 children presented with early-infancy proteinuria and progressive renal dysfunction.
• The median age of onset for proteinuria was 18 months and for renal impairment was 22 months.
• All patients progressed to end-stage renal disease (ESRD) rapidly, with common co-occurrences of hypertension and abnormal liver function.

Conclusions:

• TTC21B gene p.C518R mutations cause nephronophthisis with early-onset proteinuria and rapid progression to ESRD.
• Liver and renal dysfunction are common in these patients.
• Understanding these clinical characteristics facilitates earlier diagnosis and management.