OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with Hereditary spastic paraplegia type 3A (SPG3A) and the genotype-phenotype correlation. METHODS: A three-generation pedigree presented at Huantai Maternal and Child Health Care Hospital in March 2021 was selected as the study subject. Whole-exome sequencing (WES) and pedigree analysis was carried out. Candidate variant was validated by Sanger sequencing of the members from the pedigree. Haplotype analysis was used to trace the origin of the variant, and pathogenicity was rated based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: 2025-12). RESULTS: A c.1024C>T (p.Pro342Ser) variant of the ATL1 was identified in the four affected members, including the proband, but none of the three unaffected relatives. Haplotype analysis suggested that the variant was derived from the proband's mother and has co-segregated with the disease phenotype. Based on the guidelines of the ACMG, it was classified as likely pathogenic. CONCLUSION The ATL1 c.1024C>T (p.Pro342Ser) variant probably underlay the pathogenesis in this pedigree. Above finding has enriched the mutational spectrum of ATL1 and phenotypic spectrum of SPG3A in the Chinese population, and enabled genetic counseling for this pedigree.
Humans ; Pedigree ; Spastic Paraplegia, Hereditary/genetics* ; Male ; Female ; Asian People/genetics* ; Adult ; Haplotypes ; Membrane Proteins/genetics* ; Exome Sequencing ; GTP-Binding Proteins/genetics* ; Mutation ; Middle Aged ; China ; Genetic Association Studies ; East Asian People

OBJECTIVE: To explore the mechanism of BNIP3-mediated mitophagy in m.3635G>A related Leber's hereditary optic neuropathy (LHON). METHODS: A trans-mitochondrial cybrid cell line derived from a Chinese LHON patient carrying the m.3635G>A, diagnosed at the Eye Hospital of Wenzhou Medical University in September 2013, was selected as the study subject. A trans-mitochondrial cybrid cell line from a healthy control with an identical mitochondrial background was included as a control. Immunofluorescence, real-time quantitative PCR (RT-qPCR), and Western blotting were employed to assess the expression of autophagy-related proteins, aiming to explore the role of BNIP3-mediated mitophagy in m.3635G>A related LHON. This study was approved by the Medical Ethics Committee of the Eye Hospital of Wenzhou Medical University (Ethics No. 2023-J-096). RESULTS: Compared with the control group, the protein expression levels of autophagy-related markers LC3 (LC3-II/LC3-I) and LAMP1 were significantly reduced in the variant group (P < 0.05). Additionally, the protein levels of macroautophagy-related proteins ATG12, ATG7, and ATG5 were also significantly decreased (P < 0.05). Compared with the control cells, the mRNA and protein expression levels of mitophagy-associated protein BNIP3 were significantly reduced in the cells of the variant group (P < 0.05). Compared with the control group, both mRNA and protein expression levels of the mitophagy-related protein BNIP3 were significantly reduced in the variant group (P < 0.05). CONCLUSION The m.3635G>A inhibits BNIP3-mediated mitophagy, thereby contributing to the pathogenesis of LHON.
Humans ; Proto-Oncogene Proteins/metabolism* ; Mitophagy/genetics* ; Membrane Proteins/metabolism* ; Optic Atrophy, Hereditary, Leber/metabolism* ; Mitochondria/metabolism* ; Cell Line ; Male

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 explore the genetic characteristics of a fetus affected with Structural heart defects and renal anomalies syndrome (SHDRA). METHODS: A pedigree with SHDRA (fetus and the parents) who had visited the Affiliated Women and Children's Hospital of Ningbo University in April 2023 was selected as the study subject. Clinical data of the family were collected. A total of 10 mL of amniotic fluid cells from the fetus and 5 mL of peripheral blood samples from the parents were collected for genomic DNA extraction. Trio whole-exome sequencing (Trio-WES) was performed, and Sanger sequencing was used to validate candidate variants in the family. The identified variants were classified according to the Standards and Guidelines for the Interpretation of Sequence Variants established by the American College of Medical Genetics and Genomics (ACMG) (hereinafter referred to as the "ACMG Guidelines). Relevant research literature on SHDRA in domestic and international databases were searched for literature review. This study was approved by the Affiliated Women and Children's Hospital of Ningbo University (Ethics No. EC2023-094). RESULTS: In this family, prenatal ultrasound at 18 weeks of gestation revealed left renal multicystic dysplasia in the fetus. After birth, the infant exhibited an ostium secundum atrial septal defect, patent ductus arteriosus, and left renal multicystic dysplasia. Trio-WES revealed that the fetus had carried c.344dup (p.L116Afs*32) and c.90_104dup (p.Ala31_Ala35dup) compound heterozygous variants in the TMEM260 gene, which were respectively inherited from its father and mother. According to the ACMG guidelines, the c.344dup (p.L116Afs*32) and c.90_104dup (p.Ala31_Ala35dup) variants were classified as pathogenic (PM2_Supporting+PVS1+PP4) and likely pathogenic (PM2_Supporting+PM4+PM3+PP4), respectively. According to the literature search strategy set for this study, a total of 6 literature was retrieved, involving 25 SHDRA patients from 20 families. Together with the patients in this study, there were 14 TMEM260 gene variants, most of which were frameshift variants (7 types) and had located in exons 3, 11 and 13. The main clinical features of SHDRA were congenital heart malformation, renal abnormality and neurodevelopmental abnormality, and there was a lack of genotype-phenotype correlation. CONCLUSION The c.344dup (p.L116Afs*32) and c.90_104dup (p.Ala31_Ala35dup) variants of the TMEM260 gene probably underlay the SHDRA in this family. Above finding has provided a basis for clinical diagnosis and genetic counseling for the family.
Humans ; Female ; Pedigree ; Membrane Proteins/genetics* ; Male ; Heart Defects, Congenital/genetics* ; Kidney/abnormalities* ; Pregnancy ; Adult ; Kidney Diseases/congenital* ; Exome Sequencing ; Mutation ; Genetic Testing

OBJECTIVE: To explore the clinical phenotype, genotype and genetic characteristics for a patient with unilateral Pigmented paravenous retinochoroidal atrophy (PPRCA) and Retinitis pigmentosa (RP) in the contralateral eye. METHODS: A PPRCA pedigree which had presented at the Department of Medical Genetics of the Eye Hospital of Wenzhou Medical University in August 2021 was selected as the study subject. Clinical data of the family members were collected. The proband underwent wide-field fundus photography, wide-field autofluorescence, full-field electroretinogram (ff-ERG), visual field testing, optical coherence tomography (OCT), and fundus angiography (FFA and ICGA). Blood samples were collected from the proband and family members (parents and two sisters), and buccal mucosal cells were collected from the proband's daughter, and genomic DNA was extracted for each family member. Whole exome sequencing (WES) was performed on the proband. Candidate variants were verified using Sanger sequencing and pathogenicity analysis. This study was approved by the Medical Ethics Committee of the Eye Hospital of Wenzhou Medical University (Ethics No. 2019-134). RESULTS: Wide-angle fundus photography and autofluorescence showed that the right eye was consistent with PPRCA and the left eye with RP. OCT showed that the outer layer of the fovea was intact in the right eye, while disorganized outer segment was found in the fovea of the left eye, and outer segment atrophies outside the fovea were found in both eyes. The amplitudes of ff-ERG decreased significantly in both eyes, and the amplitudes in right eye were slightly higher than those of the left eye. Visual field showed a paracentral arcuate scotoma in the right eye and severe centripetal contraction in the left eye. FFA showed hyperfluorescence in the retinal vein distribution area caused by atrophy of retinal pigment epithelium of the right eye and hypofluorescence related to bone spicule pigmentation, in addition with mottled hypofluorescence of choroid in the left eye. ICGA showed mild paravenous retinochroidal atrophy of the right eye and diffuse choroid capillaries atrophy in the middle and peripheral area of the left eye. WES revealed that the proband had a heterozygous c.2234C>T (p.Thr745Met) variant of the CRB1 gene. Sanger sequencing confirmed that the proband and family members except the father of the proband carried the same CRB1 gene variant. Based on the criteria and guidelines for the classification of genetic variation and related consensus from the American College of Medical Genetics and Genomics (ACMG), this variant was classified as pathogenic (PM3_VeryStrong+PM1+PM2_Supporting +PP3). CONCLUSION The heterozygous c.2234C>T (p.Thr745Met) variant of the CRB1 gene may underlay the unilateral PPRCA with contralateral eye RP in this proband. Above findings have enriched the mutational spectrum of the CRB1 gene.
Humans ; Electroretinography ; Exome Sequencing ; Eye Proteins/genetics* ; Membrane Proteins/genetics* ; Mutation ; Nerve Tissue Proteins/genetics* ; Pedigree ; Phenotype ; Retinitis Pigmentosa/genetics* ; Tomography, Optical Coherence ; Retinal Degeneration ; Eye Diseases, Hereditary

OBJECTIVE: To retrospectively analyze 11 Chinese pedigrees affected with Leber congenital amaurosis (LCA) and summarize the clinical manifestations and genetic characteristics of patients. METHODS: Eleven Chinese pedigrees with probands diagnosed with LCA at the First Affiliated Hospital of Zhengzhou University from January 2020 to December 2023 were selected as the study subjects. Clinical phenotypic data of the probands were collected. Peripheral blood samples of patients and their family members were collected for the extraction of genomic DNA and whole exome sequencing. Candidate variants were validated by Sanger sequencing, qPCR assay and search of relevant databases and bioinformatic analysis. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), a diagnosis was made based on the patient's clinical phenotype, family history, and results of genetic testing. Prenatal diagnosis was provided for relevant families upon their subsequent pregnancies. This study has been approved by the Medical Ethnic Committee of the Hospital (Ethics No.: KS-2018-KY-36). RESULTS: Pedigrees 1 to 9 showed clinical features consistent with LCA and were diagnosed through genetic testing. Pedigrees 10 and 11, whilst suspected for having LCA, only had heterozygous variants detected. In total 11 novel variants were detected, including c.385C>T (p.Gln129*), c.42A>C (p.Lys14Asn) and c.1018dupA (p.Thr340Asnfs*67) of the AIPL1 gene, c.1196_1200delAAAAT (p.Asn400Thrfs*31) and exon 6-12 deletion of the SPATA7 gene, c.251A>T (p.Gln84Leu), c.875_892dupGTGCCTGGAA (p.Ser292_Gln297dup) and c.444delC (p.Ser150Glnfs*37) of the CRX gene, c.1368C>A (p.Cys456*) and c.2512A>T (p.Lys838*) of the CRB1 gene and c.3221delC (p.Pro1074Leufs*5) of the RPGRIP1 gene. CONCLUSION The phenotypic and genetic heterogeneity of LCA has posed substantial difficulty for clinical diagnosis and subtyping of the disease. Our retrospective analysis has identified novel pathogenic variants and multiple subtypes of LCA. The discovery of novel pathogenic variants and phenotypic characterization of LCA subtypes may enhance the understanding of disease etiology and clinical heterogeneity, and provide a basis for diagnosis, treatment, and genetic counseling.
Adult ; Child ; Child, Preschool ; Female ; Humans ; Male ; China ; Eye Proteins/genetics* ; Genetic Testing ; Genetic Variation ; Leber Congenital Amaurosis/diagnosis* ; Membrane Proteins/genetics* ; Mutation ; Nerve Tissue Proteins/genetics* ; Pedigree ; Phenotype ; Retrospective Studies ; East Asian People/genetics* ; Adaptor Proteins, Signal Transducing

OBJECTIVE: To explore the genetic etiology of Pontocerebellar Hypoplasia Type 2D (PCH2D) due to compound heterozygous variants of the SEPSECS gene and to conduct a literature review. METHODS: A child with PCH2D diagnosed at the Children's Hospital of Nanjing Medical University due to "motor and cognitive retardation" in June 2022 was selected as the study subject. Clinical and imaging data were collected. Genomic DNA was extracted from the peripheral blood samples of the child and her parents. Whole-exome sequencing (WES) was conducted using capture-based high-throughput sequencing technology. Candidate variants were confirmed by Sanger sequencing and bioinformatics analysis. The pathogenicity of variant was rated according to the Standards and Guidelines for the Interpretation of Sequence Variants released by American College of Medical Genetics and Genomics (ACMG). Additionally, relevant literature on PCH2D caused by SEPSECS gene variants was reviewed to assess the genotype-phenotype correlation. This study was approved by the Medical Ethics Committee of the hospital (Ethical No.: 202402022-1). RESULTS: The child, a 1-year-and-3-month-old girl, had presented with global developmental delay, progressive microcephaly, hypotonia, elevated blood lactic acid, feeding difficulties, and absent tendon reflexes. Cranial MRI indicated thinning of the splenium of the corpus callosum. Electromyography suggested peripheral neurogenic changes primarily affecting sensory nerves. WES revealed the she has harbored compound heterozygous variants of the SEPSECS gene, namely c.194A>G (p.N65S) and c.896_c.897insA (p.N299fs*2) (NM_016955), which were inherited from her father and mother, respectively. Neither of her parents had related clinical manifestations. According to the ACMG guidelines, the c.194A>G (p.N65S) variant was classified as pathogenic (PM1+PM2_Supporting+PM3+PP3), and the c.896_c.897insA (p.N299fs*2) variant was as likely pathogenic (PVS1+PM2_Supporting). A total of 18 relevant literature were retrieved, which have involved 32 patients (including this case). The p.N65S variant has been reported previously, while the p.N299fs*2 variant is novel. CONCLUSION Compound heterozygous variants in the SEPSECS gene probably underlay the pathogenesis of PCH2D in this child. Above finding has expanded the mutational and phenotypic spectrum of the SEPSECS gene.
Humans ; Female ; Infant ; Heterozygote ; Cerebellar Diseases/genetics* ; Membrane Proteins/genetics* ; Exome Sequencing ; Mutation

OBJECTIVE: To investigate the clinical phenotypes and genetic variant characteristics in children with epilepsy. METHODS: A total of 91 children with epilepsy admitted to the Women's and Children's Hospital Affiliated to Ningbo University from July 2021 to October 2022 were selected as the study subjects. Peripheral blood samples were collected from the children for whole exome sequencing. Candidate genetic variants were validated by Sanger sequencing and copy number variation sequencing (CNV-seq). The clinical phenotypes and treatment outcomes of the children with epilepsy were followed up, and an analysis of the relationship between genotype and phenotype was conducted. This study was approved by the Women's and Children's Hospital Affiliated to Ningbo University (Ethics No.: EC2020-048). RESULTS: Among the 91 children with epilepsy, 21 cases (23.08%, 21/91) were found to carry pathogenic or likely pathogenic variants. Of these, 18 cases had involved single base variant or insertional deletion, while 3 cases involved copy number variations. The gene with the highest detection rate was PRRT2 (38.10%, 8/21). Among the children with genetic variants, 47.62% (10/21) had onset during infancy, with 8 diagnosed with Benign familial infantile epilepsy (BFIE), 8 with Developmental epileptic encephalopathy (DEE), and 3 with Epileptic encephalopathy (EE). One case of Dravet syndrome (DS) and one case of Infantile spasms (IS) were also noted. The clinical manifestations of children were diverse and primarily included generalized tonic-clonic seizures and focal seizures. Among them, 52.38% (11/21) had exhibited cluster seizures, 23.81% (5/21) showed fever sensitivity, and 14.29% (3/21) experienced status epilepticus. After pharmacological treatment, 42.86% (9/21) of children had achieved complete seizure control, while 61.90% (13/21) had intellectual disability and 19.05% (4/21) had co-morbid autism spectrum disorder. CONCLUSION Pathogenic or likely pathogenic variants were identified in 23.08% of the pediatric epilepsy cases, with the PRRT2 gene being the most frequently involved. Among children carrying genetic variants, 47.62% had seizure onset during infancy. Genetic factors are an important cause of epilepsy, and early genetic testing may facilitate precise diagnosis, treatment, and prognostic evaluation.
Humans ; Female ; Male ; Epilepsy/genetics* ; Child, Preschool ; Child ; Phenotype ; Genotype ; DNA Copy Number Variations/genetics* ; Infant ; Membrane Proteins/genetics* ; Nerve Tissue Proteins/genetics* ; Adolescent ; Exome Sequencing

OBJECTIVES: The neurotoxicity of carbon monoxide (CO) to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning (DEACMP). Our previous study found that retinoic acid (RA) can suppress the neurotoxic effects of CO. This study further explores, in vivo and in vitro, the molecular mechanisms by which RA alleviates CO-induced central nervous system damage. METHODS: A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO, and a DEACMP animal model was established in adult Kunming mice. Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Annexin V/propidium iodide (PI) double staining. The transcriptional and protein expression of each gene was detected using real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting. Long noncoding RNA (lncRNA) SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes. In DEACMP mice, SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression. RESULTS: RA at 10 and 20 μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes, downregulation of SNHG15 and LINGO-1, and upregulation of brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) (all P<0.05). Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity (all P<0.05). Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels (all P<0.05). Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP (all P<0.05). CONCLUSIONS RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes, thereby reducing central nervous system injury and exerting neuroprotective effects. LncRNA SNHG15 and LINGO-1 are key molecules mediating RA-induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway. These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms.
Animals ; RNA, Long Noncoding/physiology* ; Brain-Derived Neurotrophic Factor/genetics* ; Carbon Monoxide Poisoning/complications* ; Mice ; Tretinoin/pharmacology* ; Nerve Tissue Proteins/metabolism* ; Membrane Proteins/metabolism* ; Apoptosis/drug effects* ; Hippocampus/cytology* ; Receptor, trkB/metabolism* ; Neurons/drug effects* ; Male ; Brain Diseases/etiology* ; Oligodendroglia/drug effects* ; Signal Transduction ; Cell Line

Sensorineural hearing loss is one of the most common sensory disorders. In recent years, auditory neuropathy spectrum disorders caused by mutations in the OTOF gene have garnered significant attention worldwide, marking it as the first deafness gene with breakthroughs in gene therapy. Most patients with OTOF gene mutations present with stable, congenital, or prelingual onset of hearing loss, which can range from severe to profound and even complete hearing loss. However, a minority of patients may exhibit mild to moderate progressive hearing loss or temperature-sensitive hearing loss. This review further explores the genotype-phenotype relationship of the OTOF gene based on reported cases in China and abroad. Additionally, we analyze the characteristics of the natural history of OTOF gene mutations within the Chinese population. This study aims to provide a reference for the clinical diagnosis, evaluation, and treatment of hearing loss associated with OTOF gene mutations.
Humans ; Mutation ; Phenotype ; Genotype ; Hearing Loss, Sensorineural/genetics* ; Membrane Proteins/genetics*