Functional study of the c.634C>T mutation in CCDC47 gene causing trichohepatoneurodevelopmental syndrome
ZHONG Weijun
LIU Jianan
XIONG Fu
HE Fei
Abstract：Objective To elucidate the molecular pathogenic mechanism by analyzing the clinical phenotype and genetic mutations in a family with trichothiohepatoenteric syndrome(THNS)from Guangxi,China,and to provide a basis for genetic counseling for the family.Methods Clinical phenotype analysis was performed on the patient at the Guangxi Maternal and Child Health Hospital.Peripheral blood was collected and sent to Beijing Quanpu Medical Laboratory for DNA extraction and exome sequencing to screen for genetic mutations.Family analysis was performed,and peripheral blood samples were collected from family members.Sanger sequencing verification was performed at Sangon Biotech.The following functional experiments were conducted in the Medical Genetics Laboratory of Southern Medical University:Using the pEGFP-C1 vector and restriction enzymes EcoRI and BamHI,wild-type plasmids containing CCDC47 and mutant plasmids containing the CCDC47 c.634C>T(p.Arg212*)variant were constructed.The constructed plasmids were transfected into HEK293T cells using the lipofection method.Quantitative real-time PCR and Western blotting were used to analyze mRNA and protein expression of the mutant CCDC47 gene.Immunofluorescence was employed to investigate the changes in the subcellular localization of the mutant protein,and the I-TASSER tool were used to predict alterations in the protein's tertiary structure.Results A homozygous mutation(c.634C>T,p.Arg212*)in exon 5 of the CCDC47 gene was identified in the proband,Both parents and two elder sisters were heterozygous carriers of this mutation.Compared to the wild-type,the mutant CCDC47 protein showed no significant difference in subcellular localization but exhibited markedly reduced mRNA and protein expression,along with significant structural changes in its three-dimensional conformation.Conclusion This study reports a novel CCDC47 mutation(c.634C>T,p.Arg212*)causing THNS,likely due to the substantial structural alteration and decreased expression of the mutant protein.The findings expand the mutational spectrum of the CCDC47 gene and provide critical insights for the early diagnosis of THNS and genetic counseling for the affected family.
Keywords：trichohepatoneurodevelopmental syndromeCCDC47 genedevelopmental malformationgenetic mutation
Publication Date：2025-09-20
Online Publishing Date：2025-10-22(First online date of this platform, not the publication date of the document)
Pages：6( 1168-1173 )