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Background: Alport syndrome is a genetic disorder affecting the kidneys, ears, and eyes, causing chronic kidney disease, sensorineural hearing loss, and ocular abnormalities. It results from pathogenic variants in the COL4A3, COL4A4, or COL4A5 genes, with different inheritance patterns: X-linked from COL4A5 variants, autosomal recessive from homozygous variants in COL4A3 or COL4A4, digenic from variants in both COL4A3 and COL4A4, and autosomal dominant from heterozygous variants in COL4A3 or COL4A4., Methods: We analyzed 45 patients with Alport syndrome from 11 Tunisian families to determine their clinical and genetic characteristics. Clinical data were collected retrospectively, and whole-exome sequencing was conducted on one patient from each family. Sanger sequencing validated pathogenic variants, and cascade screening extended the analysis to 53 individuals., Results: We identified nine likely pathogenic variants among 11 index cases: six novel and three known variations. Of these, five were in COL4A3, and four were in COL4A5, with variants including frameshift, nonsense, missense, and alternative splicing. Most variations affected the Gly-XY codon. Among the 45 clinically identified siblings, 30 tested positive for Alport syndrome. The cascade screening identified 3 additional affected individuals, 10 unaffected siblings, and 10 unaffected parents. The mode of inheritance was autosomal recessive in six families and X-linked in four families., Conclusions: This study is the first to screen the mutational spectrum of Alport syndrome in Tunisia. It reveals novel pathogenic variants and suggests that autosomal recessive inheritance may be more common in the Tunisian population than X-linked inheritance, contrary to existing literature., (© 2024. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Polyuria-polydipsia syndrome is a frequent symptom in pediatrics, primarily attributed to diabetes mellitus. In the context of diabetes insipidus, this syndrome can stem from central or nephrogenic factors. Sjögren's syndrome, an uncommon autoimmune disease in children, can affect multiple organs. Kidney involvement as described in adults is usually related to glomerular or tubular impairment, often linked to distal tubular acidosis. As a kidney involvement during childhood, Sjögren's syndrome has rarely been reported. Hereby, we present the case of Sjögren's syndrome revealed by polyuria-polydipsia syndrome in a 10-year-old boy., (© 2023. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Introduction: Pediatric end-stage renal disease is a rare but severe condition that causes numerous complications and impairs the quality of life of children. Kidney transplantation is the therapy of choice in pediatric end-stage renal disease., Aim: Our study aimed to identify the predictive factors of renal graft failure after kidney transplantation in Tunisian children and young adults., Methods: We conducted a retrospective bicentric study of children and young adults (age≤20 years) who had undergone renal transplantation between 1989 and 2019 in Tunisia. We analyzed long-term survival rates and complications after pediatric kidney transplantation and searched for predictive parameters for graft dysfunction. We used a univariate and a multivariate analysis to identify predictive factors of graft survival., Results: A total of 112 patients underwent 115 kidney transplantations. Graft failure occurred in 30% of the cases. The overall 1-, 3-, 5- and 10-year graft survival rates were 92%, 89.1%, 85.9% and 74.5% respectively. The following parameters strongly influenced graft survival: immunosuppressive regimen including an association other than Mycophenolate mofetil- tacrolimus and corticosteroids (p=0.002), year of transplant (p<0.0001 for 1987-2000), deceased donor (p = 0.039), underlying etiology of end-stage renal disease (p=0.045), occurrence of acute or chronic rejection (p<0.001), a urine protein greater than 0.3 g/l per day (p=0.002), post-transplant urologic complications (p=0.002), five-year creatinine level>1.28 mg/dl (p<0.001). The overall 1-, 3-, 5- and 10-year patients survival rates were 97%, 95%, 90.2% and 84.4% respectively., Conclusions: Our study identified several predictive factors of graft failure in Tunisian children and young adults undergoing renal transplantation.