1.Identification of pathological variants of SLC12A3 gene in a pedigree affected with Gitelman syndrome.
Qian MA ; Jinlin WU ; Lingyi CHE ; Xiangdong KONG
Chinese Journal of Medical Genetics 2020;37(12):1368-1370
OBJECTIVE:
To detect pathological variants of the SLC12A3 gene in a Chinese pedigree affected with Gitelman syndrome (GS).
METHODS:
Clinical data and peripheral blood samples of the proband and his family members were collected. All exons of the SLC12A3 gene were amplified by PCR and subjected to Sanger sequencing.
RESULTS:
Sanger sequencing has revealed that the proband has carried a c.486_489 delTACG (p.Ile162Met fs*8) deletion and a heterozygous c.2890C>T (p.Arg964Trp) missense variant in the SLC12A3 gene. Neither variant was reported previously and was not found among healthy controls.
CONCLUSION
The c.486_489delTACG (p.Ile162Met fs*8) and c.2890C>T (p.Arg964Trp) variants of the SLC12A3 gene probably underlay the GS in the proband. Above discovery has enriched the variant spectrum of GS.
China
;
Gitelman Syndrome/genetics*
;
Heterozygote
;
Humans
;
Mutation/genetics*
;
Pedigree
;
Solute Carrier Family 12, Member 3/genetics*
2.Genetic and clinical analysis of a pedigree affected with X-linked dominant Alport syndrome due to a novel variant of COL4A5 gene.
Qian MA ; Jinlin WU ; Lingyi CHE ; Xiangdong KONG
Chinese Journal of Medical Genetics 2021;38(5):461-464
OBJECTIVE:
To explore the genetic basis for a Chinese pedigree affected with X-linked hereditary Alport syndrome.
METHODS:
Next generation sequencing was carried out for the pedigree. Candidate variant was validated by Sanger sequencing. Pathological changes of renal basement membrane and expression of COL4A5 protein were analyzed by renal biopsy and immunofluorescence assay, respectively.
RESULTS:
All patients from the pedigree manifested progressive renal damage, gross hematuria, proteinuria and nephrotic syndrome. Renal biopsy of the proband revealed thickening of the basement membrane. No expression of the COL4A5 gene was detected by immunofluorescence. High-throughput sequencing and Sanger sequencing indicated that the proband has carried a c.3706delC (p.1236Pfs*69) variant in exon 41 of the COL4A5 gene. The same variant was also found in his mother and two brothers whom were similarly affected.
CONCLUSION
The novel c.3706delC (p.1236Pfs*69) variant of the COL4A5 gene probably underlay the pathogenesis of X-linked hereditary Alport syndrome in this pedigree. Above findings have enriched the spectrum of COL4A5 gene variants and provided a basis for the diagnosis and genetic counseling for the pedigree.
Collagen Type IV/genetics*
;
Hematuria
;
High-Throughput Nucleotide Sequencing
;
Humans
;
Male
;
Mutation
;
Nephritis, Hereditary/genetics*
;
Pedigree
3.Genetic testing and prenatal diagnosis for two Chinese pedigrees affected with Alport syndrome due to variants of COL4A5 gene.
Qian MA ; Lingyi CHE ; Xiangdong KONG
Chinese Journal of Medical Genetics 2023;40(11):1356-1359
OBJECTIVE:
To analysis variants of COL4A5 gene in two Chinese pedigrees affected with Alport syndrome (AS) and provide prenatal diagnosis for them.
METHODS:
Two unrelated ethnic Han Chinese pedigrees who had visited the First Affiliated Hospital of Zhengzhou University respectively in September 2018 and January 2020 were selected as the study subjects. Clinical data were collected, and genomic DNA was extracted from peripheral venous blood and amniotic fluid samples for genetic testing. Following next generation sequencing, candidate variants of the COL4A5 gene were verified by Sanger sequencing and bioinformatic analysis. The gender of the fetuses was determined by the presence of sex-determining region on Y (SRY).
RESULTS:
Genetic testing revealed that the proband and a fetus from pedigree 1 had both harbored a c.2723G>A (p.Gly908Glu) variant in exon 32 of the COL4A5 gene, whilst the proband and a fetus from pedigree 2 had both harbored a c.3817G>A (p.Gly1273Asp) variant in exon 44 of the COL4A5 gene. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were classified as likely pathogenic (PP2+PM2_Supporting). Following exclusion of maternal contamination, PCR amplification of the SRY region indicated that both fetuses were males.
CONCLUSION
The c.2723G>A (p.Gly908Glu) and c.3817G>A (p.Gly1273Asp) variants of the COL4A5 gene probably underlay the AS in the two pedigrees. Detection of the SRY region can reliably identify the fetal sex, which is conducive to the prenatal diagnosis. Above results have also enriched the mutational spectrum of the COL4A5 gene and provided a reference for correlating the genotype and phenotype of the AS.
Female
;
Humans
;
Male
;
Pregnancy
;
Collagen Type IV/genetics*
;
East Asian People
;
Genetic Testing
;
Nephritis, Hereditary/genetics*
;
Pedigree
;
Prenatal Diagnosis
4.Genetic analysis of a child with Dyschromatosis symmetrica hereditaria
Qian MA ; Lingyi CHE ; Xiangdong KONG
Chinese Journal of Medical Genetics 2024;41(7):849-852
Objective:To investigate the clinical and genetic features of a child with Dyschromatosis symmetrica hereditaria (DSH) and variant of the ADAR1 gene. Methods:A child who was admitted to the Department of Dermatology of the First Affiliated Hospital of Zhengzhou University in June 2020 due to irregular pigmented maculopapular rash on the dorsum of hands was selected as the study subject. Whole exome sequencing (WES) was carried out for the child and his similarly affected father, and Sanger sequencing was used to verify the candidate variant. SWISS-MODEL was used to predict the secondary and tertiary structures of the wild-type and mutant ADAR1 proteins.Results:The child, a 13-year-old boy, had symmetrical hyperpigmented and depigmented spots on the back of his hands and was clinically diagnosed with DSH. WES and Sanger sequencing results showed that he and his father had both harbored a heterozygous c. 2858dup (p.T954Dfs*20) truncating variant in exon 10 of the ADAR1 gene. Based on the guidelines from the American College of Medical Genetics and Genomics, the variant was predicted as pathogenic (PVS1+ PM2_Supporting+ PM1+ PP3). Conclusion:The c. 2858dup (p.T954Dfs*20) variant of the ADAR1 gene probably underlay the DSH in this pedigree.