1.Clinical report and genetic analysis of a child with Aicardi-Goutières syndrome type 3 due to compound heterozygous variants of RNASEH2C gene.
Juan LIU ; Jihong HU ; Rong QIN ; Yaqin DUAN ; Hongtao ZHOU ; Yujuan XIONG
Chinese Journal of Medical Genetics 2023;40(1):81-86
OBJECTIVE:
To explore the clinical characteristics and genetic etiology of a child with Aicardi-Goutières syndrome 3 (AGS3).
METHODS:
Trio whole exome sequencing was carried out for the child and his parents, and candidate variants were verified by Sanger sequencing. To further clarify their pathogenicity, the crystal structure of the variants was simulated and analyzed, and the plasmid of variants was expressed in vitro. A literature search was also carried out to summarize the phenotypic and genetic characteristics of AGS3.
RESULTS:
The child was found to harbor novel compound heterozygous variants of the RNASEH2C gene, namely c.434G>T (p.Arg145Leu) and c.494G>C (p.Ter165Ser), which were inherited from his mother and father, respectively. Analysis of protein crystal structure suggested that the c.434G>T (p.Arg145Leu) variant may affect the stability of local structure, and in vitro experiments showed that this variant can lead to protein degradation. The c.494G>C (p.Ter165Ser) variant has destroyed the stop codon, resulting in prolonged variant.
CONCLUSION
The novel compound heterozygous variants of the RNASEH2C gene probably underlay the AGS3 in this child, which has enriched the phenotypic and mutational spectrum of this disorder.
Humans
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Child
;
Mutation
;
Autoimmune Diseases of the Nervous System/genetics*
;
Nervous System Malformations/genetics*
2.Value of chromosomal microarray analysis for the diagnosis of fetuses with anomalies of central nervous system.
Peixuan CAO ; Xiangyu ZHU ; Leilei GU ; Wei LIU ; Jie LI
Chinese Journal of Medical Genetics 2023;40(2):181-185
OBJECTIVE:
To assess the value of chromosomal microarray analysis (CMA) for the diagnosis of fetuses with anomalies of the central nervous system (CNS) and summarize the outcome of the pregnancies and follow-up.
METHODS:
A total of 636 fetuses from June 2014 to December 2020 who were referred to the Prenatal Diagnosis Center of Nanjing Drum Tower Hospital due to abnormal CNS prompted by ultrasound were selected as the research subjects. Based on the ultrasound findings, the fetuses were divided into ventricular dilatation group (n = 441), choroid plexus cyst group (n = 41), enlarged posterior fossa group (n = 42), holoprosencephaly group (n = 15), corpus callosum hypoplasia group (n = 22), and other anomaly group (n = 75). Meanwhile, they were also divided into isolated (n = 504) and non-isolated (n = 132) groups based on the presence of additional abnormalities. Prenatal samples (amniotic fluid/chorionic villi/umbilical cord blood) or abortus tissue were collected for the extraction of genomic DNA and CMA assay. Outcome of the pregnancies and postnatal follow-up were summarized and subjected to statistical analysis.
RESULTS:
In total 636 fetuses with CNS anomalies (including 89 abortus tissues) were included, and 547 cases were followed up. The overall detection rate of CMA was 11.48% (73/636). The detection rates for the holoprosencephaly group, ACC group, choroid plexus cyst group, enlarged posterior fossa group, ventricular dilatation group and other anomaly group were 80% (12/15), 31.82% (7/22), 19.51% (8/41), 14.29% (6/42), 7.48% (33/441) and 9.33% (7/75), respectively. Compared with the isolated CNS anomaly group, the detection rate for the non-isolated CNS anomaly group was significantly higher (6.35% vs. 31.06%) (32/504 vs. 41/132) (χ² = 62.867, P < 0.001). Follow up showed that, for 52 fetuses with abnormal CMA results, 51 couples have opted induced labor, whilst 1 was delivered at full term with normal growth and development. Of the 434 fetuses with normal CMA results, 377 were delivered at full term (6 had developmental delay), and 57 couples had opted induced labor. The rate of adverse pregnancy outcome for non-isolated CNS abnormal fetuses was significantly higher than that of isolated CNS abnormal fetuses (26.56% vs. 10.54%) (17/64 vs. 39/370) (χ² = 12.463, P < 0.001).
CONCLUSION
Fetuses with CNS anomaly should be tested with CMA to determine the genetic cause. Most fetuses with negative CMA result have a good prognosis, but there is still a possibility for a abnormal neurological phenotype. Fetuses with CNS abnormalities in conjunct with other structural abnormalities are at increased risk for adverse pregnancy outcomes.
Female
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Pregnancy
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Humans
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Holoprosencephaly
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Prenatal Diagnosis/methods*
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Central Nervous System
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Fetus/abnormalities*
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Nervous System Malformations/genetics*
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Microarray Analysis
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Central Nervous System Diseases
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Cysts
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Chromosome Aberrations
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Ultrasonography, Prenatal/methods*
3.The p21-activated kinases in neural cytoskeletal remodeling and related neurological disorders.
Kaifan ZHANG ; Yan WANG ; Tianda FAN ; Cheng ZENG ; Zhong Sheng SUN
Protein & Cell 2022;13(1):6-25
The serine/threonine p21-activated kinases (PAKs), as main effectors of the Rho GTPases Cdc42 and Rac, represent a group of important molecular switches linking the complex cytoskeletal networks to broad neural activity. PAKs show wide expression in the brain, but they differ in specific cell types, brain regions, and developmental stages. PAKs play an essential and differential role in controlling neural cytoskeletal remodeling and are related to the development and fate of neurons as well as the structural and functional plasticity of dendritic spines. PAK-mediated actin signaling and interacting functional networks represent a common pathway frequently affected in multiple neurodevelopmental and neurodegenerative disorders. Considering specific small-molecule agonists and inhibitors for PAKs have been developed in cancer treatment, comprehensive knowledge about the role of PAKs in neural cytoskeletal remodeling will promote our understanding of the complex mechanisms underlying neurological diseases, which may also represent potential therapeutic targets of these diseases.
Animals
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Cytoskeleton/genetics*
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Humans
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Nervous System Diseases/genetics*
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Neurons/enzymology*
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Signal Transduction
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p21-Activated Kinases/metabolism*
4.Regulation of Glial Function by Noncoding RNA in Central Nervous System Disease.
Ying BAI ; Hui REN ; Liang BIAN ; You ZHOU ; Xinping WANG ; Zhongli XIONG ; Ziqi LIU ; Bing HAN ; Honghong YAO
Neuroscience Bulletin 2023;39(3):440-452
Non-coding RNAs (ncRNAs) are a class of functional RNAs that play critical roles in different diseases. NcRNAs include microRNAs, long ncRNAs, and circular RNAs. They are highly expressed in the brain and are involved in the regulation of physiological and pathophysiological processes of central nervous system (CNS) diseases. Mounting evidence indicates that ncRNAs play key roles in CNS diseases. Further elucidating the mechanisms of ncRNA underlying the process of regulating glial function that may lead to the identification of novel therapeutic targets for CNS diseases.
Humans
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RNA, Untranslated/genetics*
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MicroRNAs/genetics*
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RNA, Long Noncoding/genetics*
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RNA, Circular
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Central Nervous System Diseases/genetics*
6.Identification of a novel MLC1 mutation in a Chinese patient affected with megalencephalic leukoencephalopathy with subcortical cysts.
Xiaolu CHEN ; Haibo QU ; Tao YU ; Rong LUO
Chinese Journal of Medical Genetics 2016;33(3):316-319
OBJECTIVETo detect potential mutation of MLC1 gene in a child affected with megalencephalic leukoencephalopathy with subcortical cysts (MLC).
METHODSClinical symptoms of the patient were retrieved. Peripheral blood DNA samples from the patient, her parents and healthy controls were collected. Potential mutation of the MLC1 gene was detected by polymerase chain reaction and Sanger sequencing.
RESULTSThe patient presented with severe motor developmental delay and a giant skull. Magnetic resonance scan showed diffuse white matter swelling in bilateral hemispheres. DNA sequencing identified a novel homozygous c.177-c.180delC mutation of the MLC1 gene. The parents of the patient both carried a heterozygous mutation c.177-c.180delC but had a normal phenotype.
CONCLUSIONA novel MLC1 mutation c.177-c.180delC has been identified in a patient with MLC. The mutation is presumably disease-causing and has derived from parents who are both carriers.
Child, Preschool ; Cysts ; genetics ; Female ; Hereditary Central Nervous System Demyelinating Diseases ; genetics ; Humans ; Membrane Proteins ; genetics ; Mutation
8.Molecular biology of neuronal voltage-gated calcium channels.
Experimental & Molecular Medicine 1998;30(3):123-130
No abstract available.
Animal
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Calcium Channels/physiology*
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Calcium Channels/chemistry
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Gene Expression Regulation
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Human
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Ion Channel Gating/physiology*
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Mice
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Mutation
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Nervous System/metabolism
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Nervous System Diseases/physiopathology
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Nervous System Diseases/genetics
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Neurons/physiology*
9.Clinical and genetic analysis of a patient with Krabbe disease presented as peripheral neuropathy.
Wei WANG ; Yali QIN ; Renbin WANG ; Weihe ZHANG ; Linwei ZHANG ; Lei CUI ; Ming JIN ; Yujuan JIAO ; Jingsong JIAO
Chinese Journal of Medical Genetics 2019;36(8):821-825
OBJECTIVE:
To explore the clinical, electrophysiological and imaging features of a patient with Krabbe disease caused by GALC mutation.
METHODS:
A comprehensive analysis including clinical investigation and genetic testing was carried out.
RESULTS:
The patient presented with peripheral neuropathy with electrophysiological anomaly suggestive of asymmetric demyelinating neuropathy. Brain imaging revealed leukoencephalopathy. Genetic analysis has identified compound heterozygous mutations in exons 5 and 11 of the GALC gene, namely c.461C>A and c.1244G>A.
CONCLUSION
Krabbe disease is a group of disorders featuring substantial phenotypic heterogeneity. Genetic and enzyme testing has become indispensable for accurate diagnosis for this disease.
DNA Mutational Analysis
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Galactosylceramidase
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genetics
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Genetic Testing
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Humans
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Leukodystrophy, Globoid Cell
;
complications
;
genetics
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Mutation
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Peripheral Nervous System Diseases
;
etiology
10.Clinical and genetic analysis of a family with Aicardi-Goutières syndrome and literature review.
Taoyun JI ; Jingmin WANG ; Huijuan LI ; Lirong ZHAO ; Yan SANG ; Ye WU
Chinese Journal of Pediatrics 2014;52(11):822-827
OBJECTIVEAicardi-Goutières syndrome (AGS) is a rare early-onset genetic encephalopathy. The aim of this study was to explore the clinical, imaging and genetic features of a family with AGS, which may contribute to definite diagnosis, genetic counseling and prenatal diagnosis of this rare disease in China. We summarized the characteristics of AGS through reviewing related references.
METHODInformation of the proband and other family members as well as their DNA samples were collected. All the exons and exon-intron boundaries of pathogenic genes were amplified with PCR and were directly sequenced for genomic DNA. And we reviewed the reports of 252 cases.
RESULT(1) The proband was a 6 years plus 7 months old boy. He presented with severe developmental delay and abnormal posture mainly as torsion of limbs. By physical examination he was found to have some chilblain-like skin lesions at the end of limbs and microcephaly. The CT scan of his head displayed multiple calcification, especially in the basal ganglia. The MRI of his head displayed a hypointense signal in T1-weighted (T1W) images and a hyperintense signal in T2-weighted (T2W) in cerebral white matter and cystic lesions in temporal white matter. The younger sister of the proband presented with chilblain-like skin lesions on her face and the end of limbs had no developmental delay. The CT of her head showed multiple calcification, especially in the basal ganglia. (2) Two mutations were identified in TREX1, one was a novel nonsense mutation (c.294_295insA), and the other was a known pathogenic mutation (c.868_885del). (3) The common performances of AGS included mental retardation [92% (231/252) ], dystonia [75% (189/252)], microcephaly [63% (159/252) ], chilblain [42% (106/252) ], basal ganglia calcification [100% (252/252)], brain atrophy[88% (222/252)] and cerebral white matter lesions [86% (217/252)]. TREX1 [38% (96/252) ] and RNASEH2B [23% (58/252)]are the most common pathogenic genes.
CONCLUSIONWe determined pathogenic gene of these patients which is the basis of genetic counseling for this family. c.294_295insA mutation is a novel mutation not reported around the world yet.
Atrophy ; Autoimmune Diseases of the Nervous System ; diagnosis ; genetics ; Calcinosis ; Child ; China ; Exodeoxyribonucleases ; genetics ; Exons ; genetics ; Genetic Testing ; Humans ; Magnetic Resonance Imaging ; Male ; Mutation ; Nervous System Malformations ; diagnosis ; genetics ; Pedigree ; Phosphoproteins ; genetics