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Tang S, You J, Liu L, Ouyang H, Jiang N, Duan J, Li C, Luo Y, Zhang W, Zhan M, Liu C, Lyu G, Zhang VW, Zhao H. Expanding the mutational spectrum of ZTTK syndrome: A de novo variant with global developmental delay and malnutrition in a Chinese patient. Mol Genet Genomic Med 2023; 11:e2188. [PMID: 37488749 PMCID: PMC10422072 DOI: 10.1002/mgg3.2188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 10/23/2022] [Accepted: 02/22/2023] [Indexed: 07/26/2023] Open
Abstract
BACKGROUND Zhu-Tokita-Takenouchi-Kim (ZTTK, OMIM 617140) syndrome is a severe multisystem developmental disorder characterized by intellectual disability, developmental delay, cortical malformations, epilepsy, visual problems, musculoskeletal abnormalities, and congenital malformations. ZTTK syndrome is caused by a heterozygous pathogenic variant of the SON gene (NM_138927) at chromosome 21q22.1. The purpose of this study was to investigate the pathogenesis of a 6-month-old Chinese child who exhibited global developmental delay, muscle weakness, malnutrition, weight loss, and strabismus, brain abnormality, immunological system abnormalities. METHODS The little girl was tested for medical exome sequencing (MES) and mtDNA sequencing in trio. And, the mutation was validated by Sanger sequencing. RESULTS A novel de novo frameshift variant, c.1845_1870del26 (p.G616Sfs*61), in the SON gene was found in the proband. CONCLUSION We described a 6-month-old Chinese child with global developmental delay caused by pathogenic de novo mutation c.1845_1870del26 (p.G616Sfs*61) in the SON. Apart from a founder mutation, we reviewed the phenotypic abnormalities and genotypes in 79 individuals. The data showed that global developmental delay is accompanied by other system disorders. Our findings expanded the mutational spectrum of ZTTK syndrome and provide genetic counseling of baby with global developmental delay.
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Affiliation(s)
- Shuo Tang
- Department of Digestive System DiseasesHunan Children's HospitalChangshaChina
| | - Jieyu You
- Department of Digestive System DiseasesHunan Children's HospitalChangshaChina
| | - Li Liu
- Department of Digestive System DiseasesHunan Children's HospitalChangshaChina
| | - Hongjuan Ouyang
- Department of Digestive System DiseasesHunan Children's HospitalChangshaChina
| | - Na Jiang
- Department of Digestive System DiseasesHunan Children's HospitalChangshaChina
| | - Jiaqi Duan
- Department of Digestive System DiseasesHunan Children's HospitalChangshaChina
| | - Canlin Li
- Department of Digestive System DiseasesHunan Children's HospitalChangshaChina
| | - Yanhong Luo
- Department of Digestive System DiseasesHunan Children's HospitalChangshaChina
| | - Wenting Zhang
- Department of Digestive System DiseasesHunan Children's HospitalChangshaChina
| | - Meizheng Zhan
- Department of Digestive System DiseasesHunan Children's HospitalChangshaChina
| | - Chenxi Liu
- Department of Digestive System DiseasesHunan Children's HospitalChangshaChina
| | | | | | - Hongmei Zhao
- Department of Digestive System DiseasesHunan Children's HospitalChangshaChina
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Slezak R, Smigiel R, Rydzanicz M, Pollak A, Kosinska J, Stawinski P, Malgorzata Sasiadek M, Ploski R. Phenotypic expansion in Zhu-Tokita-Takenouchi-Kim syndrome caused by de novo variants in the SON gene. Mol Genet Genomic Med 2020; 8:e1432. [PMID: 32705777 PMCID: PMC7549597 DOI: 10.1002/mgg3.1432] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/02/2020] [Accepted: 07/10/2020] [Indexed: 12/16/2022] Open
Abstract
Background The genetic etiology of intellectual and psychomotor disability without a defined spectrum of dysmorphic features is usually monogenic. As no diagnostic criteria for such diseases are established, the clinical diagnosis becomes to be a challenge. The object of our paper is to present two patients with non‐specific clinical symptoms for whom whole‐exome‐sequencing identified the new SON mutations and thus allowed for establishing the diagnosis of Zhu‐Tokita‐Takenouchi‐Kim (ZTTK) syndrome. In both patients, the same symptoms including hypotonia, developmental and speech delay, feeding difficulties as well as frequent infections of the respiratory tract and internal ear were observed. However, both cases presented also with exceptional symptoms such as in case 1 ventriculomegaly and asymmetry of ventricles, hypoplastic left heart syndrome (HLHS), intellectual disability, intestinal malrotation, gastroparesis, and duodenal atresia and in the case 2 febrile seizures and reduced IgA levels. We will be presenting the patients and comparing them to 30 previously described cases. Methods Whole‐exome sequencing (WES) was performed on the probands’ DNA and paired‐end sequenced (2x100 bp) on HiSeq 1500. Variants considered as disease‐causing were validated in the proband and studied in all available family members by amplicon deep sequencing performed using Nextera XT Kit and sequenced on HiSeq 1500. Results We have identified two new variants in SON gene. In case 1 it has been a heterozygous frameshift variant p.(Ala1340GlnfsTer26), while in case 2 it has been a heterozygous frameshift variant, p.(Asp1640GlyfsTer7). Both variants are described for the first time and up to now, are not mentioned in any database. Conclusion As there are no precise criteria established for the clinical diagnosis of ZTTK, an identification of SON gene mutation by whole‐exome‐sequencing is the best method that allows for a diagnosis of this syndrome.
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Affiliation(s)
- Ryszard Slezak
- Department of Genetics, Wroclaw Medical University, Wroclaw, Poland
| | - Robert Smigiel
- Department of Pediatrics and Rare Disorders, Wroclaw Medical University, Wroclaw, Poland
| | | | - Agnieszka Pollak
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Joanna Kosinska
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Piotr Stawinski
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
| | | | - Rafal Ploski
- Department of Medical Genetics, Medical University of Warsaw, Warsaw, Poland
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Ueda M, Matsuki T, Fukada M, Eda S, Toya A, Iio A, Tabata H, Nakayama A. Knockdown of Son, a mouse homologue of the ZTTK syndrome gene, causes neuronal migration defects and dendritic spine abnormalities. Mol Brain 2020; 13:80. [PMID: 32448361 PMCID: PMC7245844 DOI: 10.1186/s13041-020-00622-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 05/12/2020] [Indexed: 01/08/2023] Open
Abstract
Zhu-Tokita-Takenouchi-Kim (ZTTK) syndrome, a rare congenital anomaly syndrome characterized by intellectual disability, brain malformation, facial dysmorphism, musculoskeletal abnormalities, and some visceral malformations is caused by de novo heterozygous mutations of the SON gene. The nuclear protein SON is involved in gene transcription and RNA splicing; however, the roles of SON in neural development remain undetermined. We investigated the effects of Son knockdown on neural development in mice and found that Son knockdown in neural progenitors resulted in defective migration during corticogenesis and reduced spine density on mature cortical neurons. The induction of human wild-type SON expression rescued these neural abnormalities, confirming that the abnormalities were caused by SON insufficiency. We also applied truncated SON proteins encoded by disease-associated mutant SON genes for rescue experiments and found that a truncated SON protein encoded by the most prevalent SON mutant found in ZTTK syndrome rescued the neural abnormalities while another much shorter mutant SON protein did not. These data indicate that SON insufficiency causes neuronal migration defects and dendritic spine abnormalities, which seem neuropathological bases of the neural symptoms of ZTTK syndrome. In addition, the results support that the neural abnormalities in ZTTK syndrome are caused by SON haploinsufficiency independent of the types of mutation that results in functional or dysfunctional proteins.
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Affiliation(s)
- Masashi Ueda
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, 4800392, Japan
| | - Tohru Matsuki
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, 4800392, Japan
| | - Masahide Fukada
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, 4800392, Japan
| | - Shima Eda
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, 4800392, Japan
| | - Akie Toya
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, 4800392, Japan.,Department of Neurobiochemistry, Nagoya University School of Medicine, Nagoya, Aichi, 4668560, Japan
| | - Akio Iio
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, 4800392, Japan.,Biogate Co. Ltd., 331-1 Ohmori, Yamagata, Gifu, 5012123, Japan
| | - Hidenori Tabata
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, 4800392, Japan
| | - Atsuo Nakayama
- Department of Cellular Pathology, Institute for Developmental Research, Aichi Developmental Disability Center, Kasugai, Aichi, 4800392, Japan. .,Department of Neurobiochemistry, Nagoya University School of Medicine, Nagoya, Aichi, 4668560, Japan.
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Tan Y, Duan L, Yang K, Liu Q, Wang J, Dong Z, Li Z, He Y, Yan Y, Lin L. A novel frameshift variant in SON causes Zhu-Tokita-Takenouchi-Kim Syndrome. J Clin Lab Anal 2020; 34:e23326. [PMID: 32291808 PMCID: PMC7439338 DOI: 10.1002/jcla.23326] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 03/08/2020] [Accepted: 03/14/2020] [Indexed: 12/16/2022] Open
Abstract
Background Zhu‐Tokita‐Takenouchi‐Kim syndrome is a severe multisystem developmental disorder characterized by intellectual disability, developmental delay, malformations of the cerebral cortex, epilepsy, vision problems, musculoskeletal abnormalities, and congenital malformations. This syndrome is caused by heterozygous pathogenic variants in the SON gene at chromosome 21q22.1. Objectives The aim of this study was to investigate the pathogenesis of a 4‐year‐old Chinese child who displayed severe intellectual disability, delayed psychomotor development, and facial dysmorphism. Methods A sequential detection including chromosome karyotyping, chromosome microarray analysis (CMA), and whole‐exome sequencing (WES) was performed on this child. The familial verification of WES result was conducted by Sanger sequencing. Results A de novo frameshift variant SON: c.5230delC (p.Arg1744ValfsTer29) was identified in the proband. The identical variant was not found in his family members. The frequencies of this variant in gnomAD/gnomAD_EAS databases were both none. Conclusions This study substantiates that SON: c.5230delC (p.Arg1744ValfsTer29) is a pathogenic variant of Zhu‐Tokita‐Takenouchi‐Kim syndrome and it is the first time to report Zhu‐Tokita‐Takenouchi‐Kim syndrome in China.
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Affiliation(s)
- Ya Tan
- Department of Obstetrics and Gynecology, Peking University International Hospital, Beijing, China
| | - Ling Duan
- Mianyang Maternity and Child Health Care Hospital, Sichuan, China
| | - Kai Yang
- Department of Obstetrics and Gynecology, Peking University International Hospital, Beijing, China
| | - Qian Liu
- Department of Neurological Rehabilitation, Gansu Provincial Hospital, Gansu, China
| | - Jing Wang
- Department of Obstetrics and Gynecology, Peking University International Hospital, Beijing, China
| | - Zhe Dong
- Department of Obstetrics and Gynecology, Peking University International Hospital, Beijing, China
| | - Zhi Li
- Department of Obstetrics and Gynecology, Peking University International Hospital, Beijing, China
| | - Yiwen He
- Department of Obstetrics and Gynecology, Peking University International Hospital, Beijing, China
| | - Yousheng Yan
- Department of Obstetrics and Gynecology, Peking University International Hospital, Beijing, China.,National Research Institute for Family Planning, Beijing, China
| | - Li Lin
- Department of Obstetrics and Gynecology, Peking University International Hospital, Beijing, China
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