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 relatede 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, Wangfang 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 extrimeties, 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.

Objective:To investigate the clinical phenotypic and genetic characteristics of three children with Paroxysmal kinesigenic dyskinesia (PKD) and Self-limited familial infantile epilepsy (SeLIE) caused by PRRT2 gene mutation. Methods:Three children with PKD and SeLIE caused by PRRT2 gene mutation (children 1-3) who were treated in the First Affiliated Hospital of Zhengzhou University from November 2022 to August 2023 were selected as the research subjects. A retrospective study was conducted to collect the clinical and family history data of the three children. 2 mL of peripheral venous blood from children 1-3 and parents of children 1-2 were collected (parents of children refused to undergo genetic testing and no blood samples were collected), genomic DNA was extracted, whole exome sequencing (WES) was performed, and Sanger sequencing method was used for verification. According to the Classification Standards and Guidelines for Genetic Variants formulated by the American Society of Medical Genetics and Genomics (ACMG) (hereinafter referred to as the " ACMG Guidelines" ), the pathogenicity of the variant loci detected in three children was rated, and the detrimental loci of the variant loci were analyzed by multiple bioinformatics software. This study has been approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University (Ethics No. 2024-KY-0881-002). Results:The clinical data and genetic test results of the three children in this study are as follows. ①Child 1: female, age of onset of 4 months and 10 days, with seizures, manifested as sudden cessation of movements, staring in both eyes, cyanosis of the lips, paleness, and stiffness and shaking of limbs. The results of genetic testing showed that child 1 had maternal PRRT2 gene c. 583_584dup (p. P196Afs*34) frameshift variant, which was rated as a pathogenic variant (PVS1 PM2_Supporting PP4) according to ACMG guidelines. According to the clinical manifestations and genetic test results of child 1, he was diagnosed with SeLIE and took oral sodium valproate [0.5 mL/(kg.d)], and was still taking medication at the follow-up of 2 years old, and did not have seizures again after 5 months of age. ②Child 2: male, age of onset of 10 years old, manifested as dystonia after sudden movement. The results of genetic testing showed that child 2 had PRRT2 gene mutations: paternal c. 649dupC (p.R217Pfs*8) frameshift variant and maternal c. 445C>A (p.Q149K) mutation. Among them, c. 649dupC was a reported pathogenic variant, and according to ACMG guidelines, c. 445C>A variant was rated as a variant of unknown clinical significance (PM2_Supporting), with a high probability of benignness. According to the clinical manifestations and genetic test results of the child 2, he was diagnosed with PKD, and was followed up with oral oxcarbazepine 9 mg/(kg.d) until 12 years and 2 months, and was still on the drug, and there was no recurrence of the seizure of the form of dyskinesia after taking the drug. ③Child 3: male, age of onset of 11 years old, manifested by dystonia after sudden exercise. The results of genetic testing showed that child 3 had a missense variant of PRRT2 gene c. 904G>C (p.D302H), and his parents refused genetic testing, and the source of the mutation was unknown, and the variant was rated as a variant of unknown clinical significance (PM2_Supporting+ PP3_Moderate+ PP4) according to ACMG guidelines. According to the clinical manifestations and genetic test results of child 3, he was diagnosed with PKD, and was treated with oral oxcarbazepine 10 mg/(kg.d) for 1 year and then discontinued on his own, and was followed up at the age of 17, and there was no recurrence of the seizure of the form of movement disorder after taking the drug. Conclusion:One case of SeLIE and two cases of PKD caused by PRRT2 gene mutations responded well to anti-seizure drugs. In this study, four variant loci of PRRT2 gene were found: c. 583_584dup, c. 904G>C, c. 649dupC, c. 445C>A, among which c. 583_584dup were new variants, enriching the variant spectrum of PRRT2 gene.

Objective:To analyze the clinical characteristics and genetic etiology of a child with Christianson syndrome (CS).Methods:A 1-year-and-5-month-old boy with CS diagnosed at the First Affiliated Hospital of Zhengzhou University in April 2021 was selected as the study subject. Clinical data were retrospectively analyzed. Peripheral blood samples were obtained from the child and his parents, followed by genomic DNA extraction and whole exome sequencing (WES). Candidate variant was validated by Sanger sequencing. This study has been approved by the Medical Ethics Committee of the Hospital (Ethics No. 2024-KY-1103-001).Results:The child has manifested with seizures, microcephaly, and global developmental delay. WES revealed that he has harbored a novel de novo hemizygous nonsense variant of the SLC9A6 gene, namely c. 1014G>A (p.W338*). Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as pathogenic. Conclusion:The hemizygous c. 1014G>A nonsense variant of the SLC9A6 gene probably underlay the pathogenesis in this child. Above discovery has expanded mutational spectrum of the SLC9A6 gene and enabled definite diagnosis of the child.

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

OBJECTIVE: To investigate the clinical phenotypic and genetic characteristics of three children with Paroxysmal kinesigenic dyskinesia (PKD) and Self-limited familial infantile epilepsy (SeLIE) caused by PRRT2 gene mutation. METHODS: Three children with PKD and SeLIE caused by PRRT2 gene mutation (children 1-3) who were treated in the First Affiliated Hospital of Zhengzhou University from November 2022 to August 2023 were selected as the research subjects. A retrospective study was conducted to collect the clinical and family history data of the three children. 2 mL of peripheral venous blood from children 1-3 and parents of children 1-2 were collected (parents of children refused to undergo genetic testing and no blood samples were collected), genomic DNA was extracted, whole exome sequencing (WES) was performed, and Sanger sequencing method was used for verification. According to the Classification Standards and Guidelines for Genetic Variants formulated by the American Society of Medical Genetics and Genomics (ACMG) (hereinafter referred to as the "ACMG Guidelines"), the pathogenicity of the variant loci detected in three children was rated, and the detrimental loci of the variant loci were analyzed by multiple bioinformatics software. This study has been approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University (Ethics No. 2024-KY-0881-002). RESULTS: The clinical data and genetic test results of the three children in this study are as follows. Child 1: female, age of onset of 4 months and 10 days, with seizures, manifested as sudden cessation of movements, staring in both eyes, cyanosis of the lips, paleness, and stiffness and shaking of limbs. The results of genetic testing showed that child 1 had maternal PRRT2 gene c.583_584dup (p.P196Afs*34) frameshift variant, which was rated as a pathogenic variant (PVS1 PM2_Supporting PP4) according to ACMG guidelines. According to the clinical manifestations and genetic test results of child 1, he was diagnosed with SeLIE and took oral sodium valproate [0.5 mL/(kg.d)], and was still taking medication at the follow-up of 2 years old, and did not have seizures again after 5 months of age. Child 2: male, age of onset of 10 years old, manifested as dystonia after sudden movement. The results of genetic testing showed that child 2 had PRRT2 gene mutations: paternal c.649dupC (p.R217Pfs*8) frameshift variant and maternal c.445C>A (p.Q149K) mutation. Among them, c.649dupC was a reported pathogenic variant, and according to ACMG guidelines, c.445C>A variant was rated as a variant of unknown clinical significance (PM2_Supporting), with a high probability of benignness. According to the clinical manifestations and genetic test results of the child 2, he was diagnosed with PKD, and was followed up with oral oxcarbazepine 9 mg/(kg.d) until 12 years and 2 months, and was still on the drug, and there was no recurrence of the seizure of the form of dyskinesia after taking the drug. Child 3: male, age of onset of 11 years old, manifested by dystonia after sudden exercise. The results of genetic testing showed that child 3 had a missense variant of PRRT2 gene c.904G>C (p.D302H), and his parents refused genetic testing, and the source of the mutation was unknown, and the variant was rated as a variant of unknown clinical significance (PM2_Supporting+PP3_Moderate+PP4) according to ACMG guidelines. According to the clinical manifestations and genetic test results of child 3, he was diagnosed with PKD, and was treated with oral oxcarbazepine 10 mg/(kg.d) for 1 year and then discontinued on his own, and was followed up at the age of 17, and there was no recurrence of the seizure of the form of movement disorder after taking the drug. CONCLUSION One case of SeLIE and two cases of PKD caused by PRRT2 gene mutations responded well to anti-seizure drugs. In this study, four variant loci of PRRT2 gene were found: c.583_584dup, c.904G>C, c.649dupC, c.445C>A, among which c.583_584dup were new variants, enriching the variant spectrum of PRRT2 gene.
Humans ; Male ; Nerve Tissue Proteins/genetics* ; Female ; Membrane Proteins/genetics* ; Mutation ; Child, Preschool ; Infant ; Phenotype ; Dystonia/genetics* ; Retrospective Studies ; Child

OBJECTIVE: To analyze the clinical characteristics and genetic etiology of a child with Christianson syndrome (CS). METHODS: A 1-year-and-5-month-old boy with CS diagnosed at the First Affiliated Hospital of Zhengzhou University in April 2021 was selected as the study subject. Clinical data were retrospectively analyzed. Peripheral blood samples were obtained from the child and his parents, followed by genomic DNA extraction and whole exome sequencing (WES). Candidate variant was validated by Sanger sequencing. This study has been approved by the Medical Ethics Committee of the Hospital of Zhengzhou University (Ethics No. 2024-KY-1103-001). RESULTS: The child has manifested with seizures, microcephaly, and global developmental delay. WES revealed that he has harbored a novel de novo hemizygous nonsense variant of the SLC9A6 gene, namely c.1014G>A (p.W338*). Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as pathogenic. CONCLUSION The hemizygous c.1014G>A nonsense variant of the SLC9A6 gene probably underlay the pathogenesis in this child. Above discovery has expanded mutational spectrum of the SLC9A6 gene and enabled definite diagnosis of the child.
Humans ; Male ; Infant ; Microcephaly/genetics* ; Spasms, Infantile/genetics* ; Sodium-Hydrogen Exchangers/genetics* ; Exome Sequencing ; Intellectual Disability/genetics* ; Genetic Diseases, X-Linked/genetics* ; Mutation ; Seizures/genetics* ; Ataxia ; Epilepsy ; Ocular Motility Disorders

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 relatede 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, Wangfang 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 extrimeties, 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.

Objective:To investigate the clinical phenotypic and genetic characteristics of three children with Paroxysmal kinesigenic dyskinesia (PKD) and Self-limited familial infantile epilepsy (SeLIE) caused by PRRT2 gene mutation. Methods:Three children with PKD and SeLIE caused by PRRT2 gene mutation (children 1-3) who were treated in the First Affiliated Hospital of Zhengzhou University from November 2022 to August 2023 were selected as the research subjects. A retrospective study was conducted to collect the clinical and family history data of the three children. 2 mL of peripheral venous blood from children 1-3 and parents of children 1-2 were collected (parents of children refused to undergo genetic testing and no blood samples were collected), genomic DNA was extracted, whole exome sequencing (WES) was performed, and Sanger sequencing method was used for verification. According to the Classification Standards and Guidelines for Genetic Variants formulated by the American Society of Medical Genetics and Genomics (ACMG) (hereinafter referred to as the " ACMG Guidelines" ), the pathogenicity of the variant loci detected in three children was rated, and the detrimental loci of the variant loci were analyzed by multiple bioinformatics software. This study has been approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University (Ethics No. 2024-KY-0881-002). Results:The clinical data and genetic test results of the three children in this study are as follows. ①Child 1: female, age of onset of 4 months and 10 days, with seizures, manifested as sudden cessation of movements, staring in both eyes, cyanosis of the lips, paleness, and stiffness and shaking of limbs. The results of genetic testing showed that child 1 had maternal PRRT2 gene c. 583_584dup (p. P196Afs*34) frameshift variant, which was rated as a pathogenic variant (PVS1 PM2_Supporting PP4) according to ACMG guidelines. According to the clinical manifestations and genetic test results of child 1, he was diagnosed with SeLIE and took oral sodium valproate [0.5 mL/(kg.d)], and was still taking medication at the follow-up of 2 years old, and did not have seizures again after 5 months of age. ②Child 2: male, age of onset of 10 years old, manifested as dystonia after sudden movement. The results of genetic testing showed that child 2 had PRRT2 gene mutations: paternal c. 649dupC (p.R217Pfs*8) frameshift variant and maternal c. 445C>A (p.Q149K) mutation. Among them, c. 649dupC was a reported pathogenic variant, and according to ACMG guidelines, c. 445C>A variant was rated as a variant of unknown clinical significance (PM2_Supporting), with a high probability of benignness. According to the clinical manifestations and genetic test results of the child 2, he was diagnosed with PKD, and was followed up with oral oxcarbazepine 9 mg/(kg.d) until 12 years and 2 months, and was still on the drug, and there was no recurrence of the seizure of the form of dyskinesia after taking the drug. ③Child 3: male, age of onset of 11 years old, manifested by dystonia after sudden exercise. The results of genetic testing showed that child 3 had a missense variant of PRRT2 gene c. 904G>C (p.D302H), and his parents refused genetic testing, and the source of the mutation was unknown, and the variant was rated as a variant of unknown clinical significance (PM2_Supporting+ PP3_Moderate+ PP4) according to ACMG guidelines. According to the clinical manifestations and genetic test results of child 3, he was diagnosed with PKD, and was treated with oral oxcarbazepine 10 mg/(kg.d) for 1 year and then discontinued on his own, and was followed up at the age of 17, and there was no recurrence of the seizure of the form of movement disorder after taking the drug. Conclusion:One case of SeLIE and two cases of PKD caused by PRRT2 gene mutations responded well to anti-seizure drugs. In this study, four variant loci of PRRT2 gene were found: c. 583_584dup, c. 904G>C, c. 649dupC, c. 445C>A, among which c. 583_584dup were new variants, enriching the variant spectrum of PRRT2 gene.

Objective:To analyze the clinical characteristics and genetic etiology of a child with Christianson syndrome (CS).Methods:A 1-year-and-5-month-old boy with CS diagnosed at the First Affiliated Hospital of Zhengzhou University in April 2021 was selected as the study subject. Clinical data were retrospectively analyzed. Peripheral blood samples were obtained from the child and his parents, followed by genomic DNA extraction and whole exome sequencing (WES). Candidate variant was validated by Sanger sequencing. This study has been approved by the Medical Ethics Committee of the Hospital (Ethics No. 2024-KY-1103-001).Results:The child has manifested with seizures, microcephaly, and global developmental delay. WES revealed that he has harbored a novel de novo hemizygous nonsense variant of the SLC9A6 gene, namely c. 1014G>A (p.W338*). Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as pathogenic. Conclusion:The hemizygous c. 1014G>A nonsense variant of the SLC9A6 gene probably underlay the pathogenesis in this child. Above discovery has expanded mutational spectrum of the SLC9A6 gene and enabled definite diagnosis of the child.

OBJECTIVE: To explore the prevalence and characteristics of chromosomal abnormalities in abortuses during early pregnancy with single nucleotide polymorphism microarray (SNP-array). METHODS: For 520 abortuses, copy number variations (CNVs) in chorionic villi were analyzed with SNP-array. RESULTS: In 510 (98.1%) of the samples, the analysis was successful. Among these, 57.6% (294/510) of the samples were found to harbor clinically significant chromosomal abnormalities. 38.8% of the samples (198/510) had a normal result. 2.4% (12/510) of the samples harbored benign CNVs, and 1.2% (6/510) harbored variants of uncertain significance (VOUS). Aneuploidies, polyploidies, pathogenic CNVs and uniparental disomies (UPD) had accounted for 75.2% (221/294), 13.9% (41/294), 8.2% (24/294), and 2.7% (8/294) of the samples, respectively. 45,XO was the most common finding, which was followed by trisomy 16 and trisomy 22. 69,XXY was the most common polyploidy. CONCLUSION Chromosomal abnormalities are the main cause for early miscarriage, among which aneuploidies are most common. The prevalence of aneuploidies is significantly increased among women over 35. SNP-array analysis has the advantage of high success rate, high resolution and great accuracy, but the clinical significance of microdeletions/microduplications found by SNP-array can be difficult for interpretation.
Chorionic Villi ; Chromosome Aberrations ; Chromosome Disorders ; DNA Copy Number Variations ; Female ; Genetic Testing ; Humans ; Karyotyping ; Polymorphism, Single Nucleotide ; Pregnancy