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Deng T, Xie Y. Novel homozygous mutations in TXNDC15 causing Meckel syndrome. Mol Genet Genomic Med 2024; 12:e2343. [PMID: 38156946 PMCID: PMC10958169 DOI: 10.1002/mgg3.2343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/27/2023] [Accepted: 12/07/2023] [Indexed: 01/03/2024] Open
Abstract
BACKGROUND Meckel syndrome (MKS) is the most severe form of an autosomal recessive ciliopathy and is clinically characterized by occipital encephalocele, severely polycystic kidneys, and postaxial polydactyly (toes). The association of TXNDC15-related MKS has been reported. We report the case of a homozygous mutation in the TXNDC15 gene, causing MKS14 in the Chinese population. METHODS The fetal skin tissue and parental peripheral blood were retained for whole-exome sequencing and Sanger sequencing, which investigated the potential pathogenic variants associated with MKS. RESULTS The fetus was homozygous for a mutation in the TXNDC15 gene (NM_024715.3), specifically c.560delA (p.Asn187llefsTer4), and both parents were heterozygous for this mutation. CONCLUSION Our study identified a new mutation that adds to the mutational landscape of MKS, which provide a basis for genetic counseling and the selection of reproductive options.
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Affiliation(s)
- Tianqin Deng
- Reproductive Medical CenterShenzhen Maternity & Child Healthcare HospitalShenzhenPeople's Republic of China
| | - Yuli Xie
- Neonatal Screening CenterShenzhen Maternity & Child Healthcare HospitalShenzhenPeople's Republic of China
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Zhang Q, Yang S, Chen X, Wang H, Li K, Zhang C, Liao S, Qin L, Hou Q. Identification of novel TMEM231 gene splice variants and pathological findings in a fetus with Meckel Syndrome. Front Genet 2023; 14:1252873. [PMID: 37736303 PMCID: PMC10509762 DOI: 10.3389/fgene.2023.1252873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 08/22/2023] [Indexed: 09/23/2023] Open
Abstract
Background: Meckel Syndrome (MKS, OMIM #249000) is a rare and fatal autosomal recessive ciliopathy with high clinical and genetic heterogeneity. MKS shows complex allelism with other related ciliopathies such as Joubert Syndrome (JBTS, OMIM #213300). In MKS, the formation and function of the primary cilium is defective, resulting in a multisystem disorder including occipital encephalocele, polycystic kidneys, postaxial polydactyly, liver fibrosis, central nervous system malformations and genital anomalies. This study aimed to analyze the genotype of MKS patients and investigate the correlation between genotype and phenotype. Methods: A nonconsanguineous couple who conceived four times with a fetus affected by multiorgan dysfunction and intrauterine fetal death was studied. Whole exome sequencing (WES) was performed in the proband to identify the potentially pathogenic variant. Sanger sequencing was performed in family members. In silico tools were used to analyse the pathogenicity of the identified variants. cDNA TA-cloning sequencing was performed to validate the effects of intronic variants on mRNA splicing. Quantitative real-time PCR was performed to investigate the effect of the variants on gene expression. Immunofluorescence was performed to observe pathological changes of the primary cilium in kidney tissue from the proband. Results: Two splice site variants of TMEM231 (NM_001077418.2, c.583-1G>C and c.583-2_588delinsTCCTCCC) were identified in the proband, and the two variants have not been previously reported. The parents were confirmed as carriers. The two variants were predicted to be pathogenic by in silico tools and were classified as pathogenic/likely pathogenic variants according to the American College of Medical Genetics and Genomics guideline. cDNA TA cloning analysis showed that both splice site variants caused a deletion of exon 5. RT-PCR revealed that the expression of TMEM231 was significantly decreased and immunofluorescence showed that the primary cilium was almost absent in the proband's kidney tissue. Conclusion: We reported the clinical, genetic, molecular and histochemical characterisation of a family affected by MKS. Our findings not only extended the mutation spectrum of the TMEM231 gene, but also revealed for the first time the pathological aetiology of primary cilia in humans and provide a basis for genetic counselling of the parents to their offspring.
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Affiliation(s)
- Qian Zhang
- Henan Provincial Key Laboratory of Genetic Diseases and Functional Genomics, Henan Provincial People’s Hospital, Medical Genetics Institute of Henan Province, People’s Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- National Health Commission Key Laboratory of Birth Defects Prevention, Henan Key Laboratory of Population Defects Prevention, Zhengzhou, China
| | - Shuya Yang
- People’s Hospital of Henan University, Henan University, Zhengzhou, China
| | - Xin Chen
- Henan Provincial Key Laboratory of Genetic Diseases and Functional Genomics, Henan Provincial People’s Hospital, Medical Genetics Institute of Henan Province, People’s Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- National Health Commission Key Laboratory of Birth Defects Prevention, Henan Key Laboratory of Population Defects Prevention, Zhengzhou, China
| | - Hongdan Wang
- Henan Provincial Key Laboratory of Genetic Diseases and Functional Genomics, Henan Provincial People’s Hospital, Medical Genetics Institute of Henan Province, People’s Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- National Health Commission Key Laboratory of Birth Defects Prevention, Henan Key Laboratory of Population Defects Prevention, Zhengzhou, China
| | - Keyan Li
- National Health Commission Key Laboratory of Birth Defects Prevention, Henan Key Laboratory of Population Defects Prevention, Zhengzhou, China
| | - Chaonan Zhang
- National Health Commission Key Laboratory of Birth Defects Prevention, Henan Key Laboratory of Population Defects Prevention, Zhengzhou, China
| | - Shixiu Liao
- Henan Provincial Key Laboratory of Genetic Diseases and Functional Genomics, Henan Provincial People’s Hospital, Medical Genetics Institute of Henan Province, People’s Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- National Health Commission Key Laboratory of Birth Defects Prevention, Henan Key Laboratory of Population Defects Prevention, Zhengzhou, China
| | - Litao Qin
- Henan Provincial Key Laboratory of Genetic Diseases and Functional Genomics, Henan Provincial People’s Hospital, Medical Genetics Institute of Henan Province, People’s Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- National Health Commission Key Laboratory of Birth Defects Prevention, Henan Key Laboratory of Population Defects Prevention, Zhengzhou, China
| | - Qiaofang Hou
- Henan Provincial Key Laboratory of Genetic Diseases and Functional Genomics, Henan Provincial People’s Hospital, Medical Genetics Institute of Henan Province, People’s Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
- National Health Commission Key Laboratory of Birth Defects Prevention, Henan Key Laboratory of Population Defects Prevention, Zhengzhou, China
- People’s Hospital of Henan University, Henan University, Zhengzhou, China
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