1.Clinical feature and genetic analysis of a case of X-linked alpha-thalassemia mental retardation syndrome neonate caused by ATRX gene variant and literature review.
Qianya XU ; Xinru CHENG ; Shanshan ZHANG ; Aojie CAI ; Qian ZHANG
Chinese Journal of Medical Genetics 2025;42(2):162-169
OBJECTIVE:
To explore the clinical phenotype and genetic etiology of a neonate with X-linked alpha-thalassemia mental retardation syndrome (ATR-X) caused by ATRX gene variant, and review related literature on children with ATR-X caused by ATRX gene variants.
METHODS:
A case of ATR-X neonate who was transferred to the First Affiliated Hospital of Zhengzhou University on February 11, 2022 for poor effect of treatment in the neonatology department of the hospital where he was born for 4 days due to "postnatal slow response, groaning, and cyanosis of the skin for 30 min" was selected as the study subject. 3 mL of peripheral blood was collected from the child and their parents, and genomic DNA was extracted for whole exome sequencing (WES). Sanger sequencing was used to verify the pathogenic gene variations in the child's family. The pathogenicity of genetic variant sites was assessed based on the Standards and Guidelines for the Interpretation of Sequence Variants by American College of Medical Genetics and Genomics (ACMG). The amino acid sequence conservation analysis of relevant variant proteins was conducted by the Universal Protein Resource Database (UniProt) and visual analysis of these variant proteins was performed by Swiss online protein three-dimensional modeling database (SWISS-MODEL). Using keywords such as "ATRX gene" and " X-linked alpha-thalassemia mental retardation syndrome" both in Chinese and English, relevant literature on ATR-X children caused by ATRX gene variants was retrieved from the CNKI, Wanfang Data Knowledge Service Platform, and PubMed databases, and the clinical phenotypes of ATR-X patients reported in the retrieved literature were analyzed. The literature retrieval time was set from the establishment of each database to December 31st, 2023. This study followed the research procedures approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University (Ethics No. 2023-KY-1360-002), and informed consent of clinical study was signed by the guardian of the child.
RESULTS:
The child in this study presented with symptoms such as delayed response, feeding difficulties accompanied by vomiting, low body temperature, hypotonia in all extremities, apnea, abnormal hearing screening, and a Neonatal Behavioral Neurological Assessment (NBNA) score of 19 (lower than the normal range).Hemoglobin (Hb) electrophoresis suggested the presence of α-thalassemia. The results of WES and Sanger sequencing revealed a hemizygous missense variant c.668G>A (p.C223Y) in exon 9 of the ATRX gene in the child of the study, neither of the parents of the child carried this variant, indicating that it is a de novo variant. Based on the Standards and Guidelines for the Interpretation of Sequence Variants released by ACMG, this gene variant was assessed as pathogenic (PS2+PM2_Supporting+PP3_Strong+PP4_Strong). The results of amino acid sequence analysis revealed that the pathogenic variant site normally encodes cysteine, which is highly conserved among various animal species. This pathogenic variant can lead to alterations in the hydrogen bonding structure of ATRX protein, thereby affecting its structural stability. Based on the clinical manifestations and genetic testing results of the child in this study, a diagnosis of ATR-X syndrome was established Based on the literature retrieval strategy established in this study, 13 relevant articles concerning ATR-X syndrome in children caused by ATRX gene variants were retrieved, including 5 Chinese articles and 8 English articles, involving a total of 311 ATR-X children. Including the child in this study, the total number of ATR-X children reaches 312. All 312 children were male and presented with mental retardation. Among them, 45.8% (143/312) had coexisting α-thalassemia, 45.2% (141/312) had abnormal genital appearance, 44.2% (138/312) had facial malformations, and 30.8% (96/312) had hypotonia. Other phenotypes included microcephaly, skeletal dysplasia, among others.
CONCLUSION
The ATR-X child in this study exhibit a range of clinical phenotypes, including delayed growth and development, facial malformation, abnormal genital appearance, apnea, vomiting symptoms, among others. The de novo variant of ATRX gene c.668G>A (p.C223Y) was identified as the genetic etiology. This study contributes to the expansion of the clinical phenotype spectrum and genetic variation spectrum of ATR-X children.
Humans
;
X-linked Nuclear Protein/genetics*
;
alpha-Thalassemia/genetics*
;
X-Linked Intellectual Disability/genetics*
;
Male
;
Infant, Newborn
;
Exome Sequencing
;
Mutation
3.Analysis of clinical features and ATRX gene variants in a Chinese pedigree affected with X-linked alpha thalassemia mental retardation (ATR-X) syndrome.
Rui DONG ; Yali YANG ; Hui GUO ; Min GAO ; Yuqiang LYU ; Yue LI ; Xiaomeng YANG ; Yi LIU
Chinese Journal of Medical Genetics 2023;40(12):1508-1511
OBJECTIVE:
To explore the clinical characteristics and genetic basis of two brothers featuring X-linked alpha thalassemia mental retardation (ATR-X) syndrome.
METHODS:
An infant who had presented at the Qilu Children's Hospital in 2020 for unstable upright head and inability to roll over and his family were selected as the study subjects. The clinical features of the child and one of his brothers were summarized, and their genomic DNA was subjected to targeted capture and next generation sequencing (NGS).
RESULTS:
The brothers had presented with mental retardation and facial dysmorphisms. NGS revealed that they had both harbored a hemizygous c.5275C>A variant of the ATRX gene located on the X chromosome, which was inherited from their mother.
CONCLUSION
The siblings were diagnosed with ATR-X syndrome. The discovery of the c.5275C>A variant has enriched the mutational spectrum of the ATRX gene.
Humans
;
Infant
;
Male
;
alpha-Thalassemia/diagnosis*
;
Ataxia Telangiectasia Mutated Proteins/genetics*
;
East Asian People
;
Intellectual Disability/genetics*
;
Mental Retardation, X-Linked/diagnosis*
;
Pedigree
;
X-linked Nuclear Protein/genetics*
4.Clinical features and gene mutations of primary immunodeficiency disease: an analysis of 7 cases.
Chinese Journal of Contemporary Pediatrics 2018;20(4):285-289
This research investigated the clinical features of immunodeficiency disease and the features of the mutation of its pathogenic genes. All 7 patients were boys aged 5 months to 4 years and 6 months and had a history of recurrent respiratory infection and pneumonia, low levels of IgM and IgG, and abnormal absolute values or percentages of lymphocyte subsets. High-throughput sequencing showed c.1684C>T mutations in the BTK gene in patient 1 and IVS8+2T>C splice site mutations in the BTK gene in patient 2. Both of these mutations came from their mothers. Patients 3, 4, and 5 had mutations in the IL2RG gene, i.e., c.298C>T, IVS3-2A>G, and c.164T>A, among which c.164T>A mutations had not been reported. Patient 6 had c.204C>G mutations in the RAG2 gene. Patient 7 had complex heterozygous mutations of c.913C>T and c.824G>A in the RAG2 gene, which came from his father and mother, respectively. Patients with immunodeficiency disease have abnormal immunological indices, and high-throughput sequencing helps to make a definite diagnosis.
Agammaglobulinaemia Tyrosine Kinase
;
Agammaglobulinemia
;
genetics
;
Child, Preschool
;
Computational Biology
;
DNA-Binding Proteins
;
genetics
;
Genetic Diseases, X-Linked
;
genetics
;
High-Throughput Nucleotide Sequencing
;
Humans
;
Immunologic Deficiency Syndromes
;
genetics
;
therapy
;
Infant
;
Interleukin Receptor Common gamma Subunit
;
genetics
;
Male
;
Mutation
;
Nuclear Proteins
;
genetics
;
Protein-Tyrosine Kinases
;
genetics
5.ERK1/2-mediated Cytoplasmic Accumulation of hnRNPK Antagonizes TRAIL-induced Apoptosis through Upregulation of XIAP in H1299 Cells.
Wen Si HUANG ; Feng Mei XU ; Qing Zhong ZENG ; Xiao Hui LIU ; Xue Juan GAO ; Lang Xia LIU
Biomedical and Environmental Sciences 2017;30(7):473-481
OBJECTIVETumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance greatly limits the clinical therapeutic efficacy of TRAIL. Elucidating the molecular mechanism underlying TRAIL resistance will be fundamental to resolving this problem.
METHODSNuclear and cytoplasmic protein extraction and immuno?uorescence (IF) assay were used to detect changes in heterogeneous nuclear ribonucleoprotein K (hnRNPK) localization in H1299 cells. The evaluation of cell apoptosis in cells transfected with GFP-hnRNPK, GFP-hnRNPK S284/353A, or GFP-hnRNPK S284/353D mutant was performed using cleaved caspase-3 antibody. The gene expression of XIAP was tested by quantitative RT-PCR.
RESULTSPreviously, we reported that hnRNPK antagonized TRAIL-induced apoptosis through inhibition of PKC-mediated GSK3β phosphorylation. In this study, we further demonstrate that TRAIL treatment induces cytoplasmic accumulation of hnRNPK in H1299 cells. The hnRNPK localized in the cytoplasm has a higher capacity to antagonize TRAIL-induced apoptosis. Both ERK1/2 signaling inhibitor U0126 and ERK-phosphoacceptor-site mutant (GFP-hnRNPK S284/353A) diminish cytoplasmic accumulation of hnRNPK induced by TRAIL. Moreover, we show that XIAP is involved in hnRNPK-mediated TRAIL resistance in H1299 cells.
CONCLUSIONTaken together, these results give new insights into the understanding of the molecular mechanism associated with TRAIL resistance in lung adenocarcinoma.
Apoptosis ; physiology ; Cell Line, Tumor ; Gene Expression Regulation ; physiology ; Heterogeneous-Nuclear Ribonucleoprotein K ; genetics ; metabolism ; Humans ; Mitogen-Activated Protein Kinase 1 ; genetics ; metabolism ; Mitogen-Activated Protein Kinase 3 ; genetics ; metabolism ; TNF-Related Apoptosis-Inducing Ligand ; genetics ; metabolism ; Up-Regulation ; physiology ; X-Linked Inhibitor of Apoptosis Protein ; genetics ; metabolism
6.Structural basis for DAXX interaction with ATRX.
Xiaoman WANG ; Yiyue ZHAO ; Jian ZHANG ; Yong CHEN
Protein & Cell 2017;8(10):767-771
7.Structural and biochemical characterization of DAXX-ATRX interaction.
Zhuang LI ; Dan ZHAO ; Bin XIANG ; Haitao LI
Protein & Cell 2017;8(10):762-766
8.Mutation analysis for a Chinese family featuring X-linked alpha thalassemia/mental retardation syndrome.
Shao-bin LIN ; Hong-yu SUN ; Xin-ming SONG ; Lu-ming CHEN ; Min-lian DU ; Zheng CHEN
Chinese Journal of Medical Genetics 2013;30(6):654-658
OBJECTIVETo identify potential mutation in a Chinese family featuring X-linked alpha thalassemia/mental retardation syndrome (ATR-X).
METHODSBased on clinical symptoms and inheritance pattern, linkage analysis of X chromosome short tandem repeats (X-STR) loci was carried out to locate the candidate gene. Subsequently, sequences of exons and exon-intron boundaries of the candidate gene were amplified with polymerase chain reaction (PCR). Potential mutations were detected by direct DNA sequencing. All patients were also analyzed for the trait of thalassemia.
RESULTSLinkage analysis indicated the candidate gene to be ATRX. Subsequently, a homozygous missense mutation c.736C>T (p.R246C) was found in exon 9 of ATRX in all of the 3 patients. And a heterozygous mutation c.736C>T (p.R246C) was also identified in the patient's mother and grandmother. Similar mutations were not detected in other members of the family. Alpha thalassemia was detected in the proband and another patient, whose genotypes were determined as -α(3.7)/αα and --(sea)/αα, respectively.
CONCLUSIONMissense mutation of c.736C>T in ATRX gene is a mutation hotspot, and p.R246C may disturb the function of ATRX-DNMT3-DNMT3L domain (ADD), which may be responsible for the disease in this family.
Asian Continental Ancestry Group ; genetics ; Child, Preschool ; DNA Helicases ; genetics ; DNA Mutational Analysis ; methods ; Female ; Humans ; Male ; Mental Retardation, X-Linked ; genetics ; Mutation, Missense ; Nuclear Proteins ; genetics ; Pedigree ; X-linked Nuclear Protein ; alpha-Thalassemia ; genetics
9.Linkage analysis of X-linked nuclear protein gene in Smith-Fineman-Myers syndrome.
Qiji LIU ; Yaoqin GONG ; Bingxi CHEN ; Chenhong GUO ; Jiangxia LI ; Yishou GUO
Chinese Journal of Medical Genetics 2002;19(1):22-25
OBJECTIVETo determine the linkage between Smith-Fineman-Myers syndrome (SFMS) and X-linked nuclear protein(XNP) locus.
METHODSPolymerase chain reaction and denaturing polyacrylamide gel electrophoresis were used to genotype two polymorphic short tandem repeats within XNP gene.
RESULTSOne of the two short tandem repeats was informative in SFMS family from Shandong, China. Recombination between SFMS locus and XNP gene was observed in the SFMS family.
CONCLUSIONXNP gene is not associated with the disease in the SFMS family from Shandong, China. SFMS exhibits locus heterogeneity at molecular level.
Abnormalities, Multiple ; genetics ; Craniofacial Abnormalities ; genetics ; DNA Helicases ; Female ; Genetic Linkage ; Growth Disorders ; genetics ; Humans ; Intellectual Disability ; genetics ; Male ; Muscle Hypotonia ; genetics ; Nuclear Proteins ; genetics ; Pedigree ; Phenotype ; Polymorphism, Genetic ; Recombination, Genetic ; Syndrome ; X Chromosome ; X-linked Nuclear Protein

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