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Zhang X, Lu H, Yang H, Ji Y, Liu H, Liu W, Li J, Yang Z, Sun W. Genotype-phenotype correlation of deletions and duplications of 4p: case reports and literature review. Front Genet 2023; 14:1174314. [PMID: 37388934 PMCID: PMC10300434 DOI: 10.3389/fgene.2023.1174314] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 05/30/2023] [Indexed: 07/01/2023] Open
Abstract
Structural rearrangements of chromosome 4p gives rise to a group of rare genomic disorders that mainly result in two different clinical entities: Wolf-Hirschhorn syndrome (WHS) and partial 4p trisomy. The severity of the phenotype depends on the size of the deletion or locus duplication. Here, we present two unrelated individuals with a copy number variation of chromosome 4p. Inverted duplication deletions (inv dup-del) in 4p are particularly rare. Case 1 describes a 15-year-old girl with a 1.055 Mb deletion of terminal 4p, distal to the recognized critical region of WHS, and a large duplication of 9.6 Mb in size from 4p16.3 to p16.1. She had postnatal development delay, intellectual disability (especially pronounced in speech), seizure/electroencephalogram anomalies, and facial dysmorphic features. This unusual chromosomal imbalance resulted in the WHS phenotype rather than the 4p trisomy syndrome phenotype. Case 2 describes a 21-month-old boy with a 1.386 Mb terminal 4p deletion who presented with slight developmental delay, borderline intellectual disability, and seizures. Combined with previous reported cases of 4 pter del-dup or pure 4p terminal deletions, our observations suggest that terminal chromosome 4p deletion is more pathogenic than the concomitant partial 4p duplication, and some regions of the 4p terminal may have regulatory effects on the remaining region of 4p. About nine cases have been reported thus far to date, and our study delineates further genotype-phenotype correlations about terminal 4p duplication-deletions for predicting disease prognosis and patient counseling.
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Affiliation(s)
- Xuan Zhang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Hongjuan Lu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Hanran Yang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | | | - Huixin Liu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Wenjian Liu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Jiayi Li
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Zhixian Yang
- Department of Pediatrics, Peking University First Hospital, Beijing, China
| | - Wei Sun
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
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Yang Q, Gong D, Yi S, Luo J, Zhang Q. Case report: A de novo NSD2 truncating variant in a child with Rauch-Steindl syndrome. Front Pediatr 2023; 11:1064783. [PMID: 37351323 PMCID: PMC10282739 DOI: 10.3389/fped.2023.1064783] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 05/22/2023] [Indexed: 06/24/2023] Open
Abstract
Wolf-Hirschhorn syndrome (WHS) is a rare genetic disorder caused by a heterozygous deletion on chromosome 4p16.3, which is called the WHS critical region (WHSC). The major features of this disorder, including "Greek warrior helmet" facies, delayed growth, intellectual disability, seizures, and skeletal abnormalities, are caused by the combined haploinsufficiency of multiple genes. The WHS candidate 1 (WHSC1) gene, also known as NSD2, is located in the WHSC and has been reported to associate with Rauch-Steindl syndrome (RSS,OMIM 619695). RSS is a highly heterogeneous disease characterized by mild developmental delay, prenatal-onset growth restriction, low body mass index, and characteristic facial features distinct from WHS. In this report, using whole exome sequencing (WES), we identified a novel de novo heterozygous NSD2 truncating variant in a 7-year-old Chinese girl with Rauch-Steindl syndrome, including failure to thrive, facial dysmorphisms, developmental delay, intellectual disability, and hypotonia. These findings further support that haploinsufficiency of NSD2 is necessary for WHS, and molecular genetic testing is more accurate to diagnose these patients. The novel variant uncovered in this study further expands the mutation spectrum of NSD2.
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Affiliation(s)
- Qi Yang
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Di Gong
- Department of School Infirmary, Guangxi Minzu University, Nanning, China
| | - Shang Yi
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Jingsi Luo
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Qinle Zhang
- Guangxi Key Laboratory of Birth Defects Research and Prevention, Guangxi Key Laboratory of Reproductive Health and Birth Defects Prevention, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Department of Genetic and Metabolic Central Laboratory, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
- Guangxi Key Laboratory of Birth Defects and Stem Cell Biobank, Nanning, China
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Boczek NJ, Lahner CA, Nguyen TM, Ferber MJ, Hasadsri L, Thorland EC, Niu Z, Gavrilova RH. Developmental delay and failure to thrive associated with a loss-of-function variant in WHSC1 (NSD2). Am J Med Genet A 2018; 176:2798-2802. [PMID: 30345613 DOI: 10.1002/ajmg.a.40498] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/12/2018] [Accepted: 07/14/2018] [Indexed: 11/07/2022]
Abstract
Wolf-Hirschhorn syndrome (WHS) is a microdeletion syndrome characterized by distinctive facial features consisting of "Greek warrior helmet" appearance, prenatal and postnatal growth deficiency, developmental disability, and seizures. This disorder is caused by heterozygous deletions on chromosome 4p16.3 often identified by cytogenetic techniques. Many groups have attempted to identify the critical region within this deletion to establish which genes are responsible for WHS. Herein, clinical whole exome sequencing (WES) was performed on a child with developmental delays, mild facial dysmorphisms, short stature, failure to thrive, and microcephaly, and revealed a de novo frameshift variant, c.1676_1679del (p.Arg559Tfs*38), in WHSC1 (NSD2). While WHSC1 falls within the WHS critical region, individuals with only disruption of this gene have only recently been described in the literature. Loss-of-function de novo variations in WHSC1 were identified in large developmental delay, autism, diagnostic, and congenital cardiac cohorts, as well as recent case reports, suggesting that de novo loss-of-function WHSC1 variants may be related to disease. These findings, along with our patient suggest that loss-of-function variation in WHSC1 may lead to a mild form of Wolf-Hirschhorn syndrome, and also may suggest that the developmental delays, facial dysmorphisms, and short stature seen in WHS may be due to disruption of WHSC1 gene.
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Affiliation(s)
- Nicole J Boczek
- Department of Laboratory Medicine and Pathology; Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Carrie A Lahner
- Department of Laboratory Medicine and Pathology; Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Thuy-Mi Nguyen
- Department of Laboratory Medicine and Pathology; Genomics Laboratory, Mayo Clinic, Rochester, Minnesota.,Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota
| | - Matthew J Ferber
- Department of Laboratory Medicine and Pathology; Genomics Laboratory, Mayo Clinic, Rochester, Minnesota.,Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota
| | - Linda Hasadsri
- Department of Laboratory Medicine and Pathology; Genomics Laboratory, Mayo Clinic, Rochester, Minnesota
| | - Erik C Thorland
- Department of Laboratory Medicine and Pathology; Genomics Laboratory, Mayo Clinic, Rochester, Minnesota.,Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota
| | - Zhiyv Niu
- Department of Laboratory Medicine and Pathology; Genomics Laboratory, Mayo Clinic, Rochester, Minnesota.,Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota
| | - Ralitza H Gavrilova
- Department of Clinical Genomics, Mayo Clinic, Rochester, Minnesota.,Department of Neurology, Mayo Clinic, Rochester, Minnesota
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