TY - JOUR
T1 - Detection of a splice site variant in a patient with glomerulopathy and fibronectin deposits
AU - Tsuji, Yurika
AU - Nozu, Kandai
AU - Sofue, Tadashi
AU - Hara, Shigeo
AU - Nakanishi, Keita
AU - Yamamura, Tomohiko
AU - Minamikawa, Shogo
AU - Nozu, Yoshimi
AU - Kaito, Hiroshi
AU - Fujimura, Junya
AU - Horinouchi, Tomoko
AU - Morisada, Naoya
AU - Morioka, Ichiro
AU - Taniguchi-Ikeda, Mariko
AU - Matsuo, Masafumi
AU - Iijima, Kazumoto
N1 - Funding Information:
This study was supported by a grant from the Ministry of Health, Labour, and Welfare (Japan) for Research on Rare Intractable Diseases in the Kidney and Urinary Tract (H24-nanchitou (nan)-ippan-041 to K.I.) in the “Research on Measures for Intractable Diseases” Project; and a Grant-in-Aid for Scientific Research (KAKENHI) from the Ministry of Education, Culture, Sports, Science and Technology of Japan (Subject ID: 15K09691 to K.N. and 26293203 to K.I.).
PY - 2018/2
Y1 - 2018/2
N2 - Background/Aims: Glomerulopathy with fibronectin deposits (GFND; OMIM: 601894) is a very rare inherited kidney disease caused by pathogenic variants in the FN1 gene. Only 9 exonic pathogenic variants in FN1, 9 at the heparin-binding site, and 1 at the integrin-binding site have been reported. No intronic variants in FN1 have been detected. Methods: We found a pathogenic intronic variant in intron 36 (c.5888-2A>G) located at the heparin-binding site. To determine whether this mutation influences splicing processes, we conducted RT-PCR analysis and an in vitro splicing assay using minigene construction. Results: RT-PCR using RNA extracted from leukocytes of the proband failed because of the low expression of FN1 mRNA in leukocytes. We conducted in vitro functional splicing analysis using minigenes and found that c.5888-2A>G caused a 12 bp deletion at exon 37 by the activation of a novel splicing acceptor site within exon 37. We were able to detect the same abnormal transcript in mRNA extracted from the patient's urinary sediment and confirmed the pathogenicity of c.5888-2A>G by both RT-PCR using the patient sample and an in vitro splicing assay. Conclusion: Intronic variants can cause GFND. Minigene analysis is useful for determining the pathogenicity of the intronic variants and could be used for all inherited kidney diseases.
AB - Background/Aims: Glomerulopathy with fibronectin deposits (GFND; OMIM: 601894) is a very rare inherited kidney disease caused by pathogenic variants in the FN1 gene. Only 9 exonic pathogenic variants in FN1, 9 at the heparin-binding site, and 1 at the integrin-binding site have been reported. No intronic variants in FN1 have been detected. Methods: We found a pathogenic intronic variant in intron 36 (c.5888-2A>G) located at the heparin-binding site. To determine whether this mutation influences splicing processes, we conducted RT-PCR analysis and an in vitro splicing assay using minigene construction. Results: RT-PCR using RNA extracted from leukocytes of the proband failed because of the low expression of FN1 mRNA in leukocytes. We conducted in vitro functional splicing analysis using minigenes and found that c.5888-2A>G caused a 12 bp deletion at exon 37 by the activation of a novel splicing acceptor site within exon 37. We were able to detect the same abnormal transcript in mRNA extracted from the patient's urinary sediment and confirmed the pathogenicity of c.5888-2A>G by both RT-PCR using the patient sample and an in vitro splicing assay. Conclusion: Intronic variants can cause GFND. Minigene analysis is useful for determining the pathogenicity of the intronic variants and could be used for all inherited kidney diseases.
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U2 - 10.1159/000484209
DO - 10.1159/000484209
M3 - Article
C2 - 29131116
AN - SCOPUS:85033451710
VL - 138
SP - 166
EP - 171
JO - Nephron
JF - Nephron
SN - 1660-8151
IS - 2
ER -