Genotype and phenotype analysis of children with autosomal dominant inheritance Alport syndrome / 中华实用儿科临床杂志

ABSTRACT

Objective:To analyze the clinicopathological and gene mutation characteristics of children with autosomal dominant inheritance Alport syndrome (ADAS), and to improve the understanding of ADAS.Methods:Ten children with ADAS diagnosed in the Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from September 2016 to February 2020 were enrolled.The clinicopathological and gene mutation features were retrospectively analyzed, and the patients were followed up.Results:(1) The median age at diagnosis was 5.7 (2.4, 9.8) years.Of 10 children, 6 cases (60.0%) showed a family history of renal failure, 4 cases (40.0%) presented with hematuria and proteinuria at diagnosis, and 2 cases (20.0%) suffered a high-frequency hearing loss.Renal biopsy showed extensive splitting and lamellation of the glomerular basement membrane (GBM) dense layer in 4 cases (40.0%), and segmental splitting and lamellation in 6 cases (60.0%). (2)Among 10 children, 4 cases (40.0%) were heterozygous mutations of COL4A3 gene, including 2 point mutations of glycine, and 2 splicing mutations.The other 6 cases (60.0%) were heterozygous mutations of COL4A4 gene, including collagen glycine point mutations in 4 cases, nonsense mutation in 1 case and large deletion in 1 case.Six mutations were new and never reported before. Conclusions:The early clinical presentations of children with ADAS are often atypical and extrarenal manifestations are less common.The GBM dense layer is mainly featured by segmental splitting and lamellation.Glycine point mutations account for the majority of the gene mutations.