{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T09:47:27Z","timestamp":1789984047863,"version":"4.0.1"},"reference-count":23,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2023,1,13]],"date-time":"2023-01-13T00:00:00Z","timestamp":1673568000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Pediatr."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>X-linked Alport syndrome (XLAS) is caused by pathogenic variants in <jats:italic>COL4A5<\/jats:italic> and is characterized by progressive kidney disease, hearing loss, and ocular abnormalities.The aim of this study was to identify gene mutations in a Chinese family with XLAS, confirm a diagnosis, and provide an accurate genetic counseling.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>The proband was a 5-year-old male with microscopic hematuria and a family history of renal disease in 5 relatives.His relatives had microhematuria with or without proteinuria. His maternal uncle developed renal failure at the age of 35 years. He was evaluated by renal biopsy,whole-exome sequencing (WES) and whole-genome sequencing (WGS) for Alport syndrome. RT-PCR and cDNA Sanger sequencing were performed on RNA extracted from the skin of the proband. Then, a splicing reporter minigene assay was used to examine the effect of the variation on the splicing of the primary transcript in transfected cells.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Pathological examination of the kidney of the proband revealed diffuse thinning of the glomerular basement membrane, and immunofluorescence analysis indicated normal expression of the <jats:italic>\u03b1<\/jats:italic>5 chain in the basement membrane. No phenotype-associated candidate variant was detected in the proband <jats:italic>via<\/jats:italic> WES. A novel deep intronic <jats:italic>COL4A5<\/jats:italic> variant (c.385\u2013716G\u2009&amp;gt;\u2009A), which is segregated with disease in this family, was identified using WGS. In-vitro minigene assay and in-vivo RT-PCR analysis demonstrated that the variant could produce both normal and abnormal transcripts. The abnormal transcripts showed that the variant activated a cryptic splice site, introducing a 147\u2005bp pseudoexon into the mRNA sequence and consequently generating a premature termination codon (<jats:italic>p<\/jats:italic>.G129Afs*38) and leading to frameshifting and truncation of the <jats:italic>\u03b1<\/jats:italic>5 (collagen IV) protein.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>This is the first report of the novel c.385\u2013716G\u2009&amp;gt;\u2009A splicing mutation in the COL4A5 gene, which illustrates the importance of performing WGS to find additional mutations in WES-negative patients with highly suspected forms of genetic diseases. The same results obtained from the in-vitro and in-vivo splicing experiments confirm the consistency between the minigene assay and RT-PCR analysis. In addition, this study highlights the importance of functional analysis in diagnosis and genetic counseling in AS.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fped.2022.1009188","type":"journal-article","created":{"date-parts":[[2023,1,11]],"date-time":"2023-01-11T06:00:47Z","timestamp":1673416847000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":7,"title":["A deep intronic splice variant of the COL4A5 gene in a Chinese family with X-linked Alport syndrome"],"prefix":"10.3389","volume":"10","author":[{"given":"Pei","family":"Qian","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ying","family":"Bao","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hui-mei","family":"Huang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lei","family":"Suo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yan","family":"Han","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhi-juan","family":"Li","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Min","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2023,1,13]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"e1","DOI":"10.1038\/ejhg.2014.254","article-title":"Clinical utility gene card for: alport syndrome - 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