1.Management of hepatolenticular degeneration during pregnancy.
Jie BAI ; Su Jun ZHENG ; Zhong Ping DUAN
Chinese Journal of Hepatology 2022;30(1):107-109
Hepatolenticular degeneration (Wilson's disease, WD) is a kind of autosomal recessive genetic disease characterized by disorders of copper metabolism. It is caused by mutations in the ATP7B gene, resulting in impaired excretion of copper into the bile, and then pathological deposition in the liver, brain, and other organs. Early diagnosis and treatment can significantly improve the prognosis of patients with WD. However, there is still no clear consensus on the treatment and management of WD during pregnancy. Herein, the clinical management of WD during pregnancy is summarized for clinicians' reference.
Copper
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Copper-Transporting ATPases/genetics*
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Female
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Hepatolenticular Degeneration/therapy*
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Humans
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Mutation
;
Pregnancy
2.Analysis of clinical phenotypes and ATP7B gene variants in 75 children patients with Wilson' s disease.
Pan LIU ; Fengyu CHE ; Chang SHU ; Yarong LI ; Xiaoguai LIU
Chinese Journal of Medical Genetics 2022;39(4):357-361
OBJECTIVE:
To analyze the clinical phenotypes and ATP7B gene variants among children patients with Wilson' s disease from Northwestern China.
METHODS:
The clinical features and variants of the ATP7B gene among 75 children with hepatic Wilson' s disease were retrospectively analyzed.
RESULTS:
Among the 75 cases, 4 were presymptomatic, 59 had isolated transaminase elevation, 12 had acute and/or chronic liver diseases. Nine children were found to harbor homozygous variants, 64 harbored compound heterozygous variants, and two only had heterozygous variants of the ATP7B gene. In total 49 variants were detected, with common variants including c.2333G>T (p.Arg778Leu), c.2621C>T (p.Ala874Val) and c.2975C>T (Pro992Leu), which yielded allelic frequencies of 28.7%, 12.7% and 9.3%, respectively. Six novel variants were detected, which included c.1908dupC (p.Asn637Glnfs*118), c.4179_4180insC (p.Pro1394Profs*15), c.1604A>G (p.Glu535Gly), c.2278C>T (p.Pro760Ser), c.3008C>A (p.Ala1003Glu) and c.3532A>C (p.Thr1178Pro). Except for c.1604A>G (p.Glu535Gly), the remainder five were all predicted to be likely pathogenic. No significant correlation was found between genotype and phenotype among the patients.
CONCLUSION
The common mutation types of the ATP7B gene among patients with hepatic Wilson disease in Northwestern China are c.2333G>T (p.Arg778Leu), c.2621C>T (p.Ala874Val) and c.2975C>T (p.Pro992Leu), there is no significant correlation between their genotypes and phenotypes.
Copper-Transporting ATPases/genetics*
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Genotype
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Hepatolenticular Degeneration/genetics*
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Humans
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Mutation
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Phenotype
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Retrospective Studies
3.Currently Clinical Views on Genetics of Wilson's Disease.
Chen CHEN ; Bo SHEN ; Jia-Jia XIAO ; Rong WU ; Sarah Jane Duff CANNING ; Xiao-Ping WANG
Chinese Medical Journal 2015;128(13):1826-1830
OBJECTIVEThe objective of this study was to review the research on clinical genetics of Wilson's disease (WD).
DATA SOURCESWe searched documents from PubMed and Wanfang databases both in English and Chinese up to 2014 using the keywords WD in combination with genetic, ATP7B gene, gene mutation, genotype, phenotype.
STUDY SELECTIONPublications about the ATP7B gene and protein function associated with clinical features were selected.
RESULTSWilson's disease, also named hepatolenticular degeneration, is an autosomal recessive genetic disorder characterized by abnormal copper metabolism caused by mutations to the copper-transporting gene ATP7B. Decreased biliary copper excretion and reduced incorporation of copper into apoceruloplasmin caused by defunctionalization of ATP7B protein lead to accumulation of copper in many tissues and organs, including liver, brain, and cornea, finally resulting in liver disease and extrapyramidal symptoms. It is the most common genetic neurological disorder in the onset of adolescents, second to muscular dystrophy in China. Early diagnosis and medical therapy are of great significance for improving the prognosis of WD patients. However, diagnosis of this disease is usually difficult because of its complicated phenotypes. In the last 10 years, an increasing number of clinical studies have used molecular genetics techniques. Improved diagnosis and prediction of the progression of this disease at the molecular level will aid in the development of more individualized and effective interventions, which is a key to transition from molecular genetic research to the clinical study.
CONCLUSIONSClinical genetics studies are necessary to understand the mechanism underlying WD at the molecular level from the genotype to the phenotype. Clinical genetics research benefits newly emerging medical treatments including stem cell transplantation and gene therapy for WD patients.
Adenosine Triphosphatases ; genetics ; Cation Transport Proteins ; genetics ; Copper-transporting ATPases ; Hepatolenticular Degeneration ; genetics ; Humans ; Phenotype
4.Synonymous variants of the ATP7B gene may cause abnormal splicing of mRNA by affecting the exonic splicing enhancers.
Xiaoying ZHOU ; Bixia ZHENG ; Zhifeng LIU ; Yu JIN
Chinese Journal of Medical Genetics 2020;37(11):1236-1240
OBJECTIVE:
To explore the effect of rare synonymous variants of the ATP7B gene on the splicing of its precursor mRNA.
METHODS:
A total of 248 rare synonymous variants with allelic frequency of <0.005 were retrieved from the ExAc database. Human Splicing Finder (HSF) was used to predict their effect on the splicing of precursor mRNA. And ESE Finder 3.0 was used to predict the effect of such variants on the binding ability of SR protein family. Rare synonymous variants affecting the binding of two or more SR proteins were selected and verified with an in vitro mini gene splicing report system.
RESULTS:
HSF analysis indicated that 136 of the 248 rare synonymous variants may destroy the exonic splicing enhancer (ESE) motif. Analysis using ESE Finder 3.0 indicated that 19 of them may affect the binding of two or more SR proteins at the same time. In vitro mini gene experiment confirmed that the c.1620C>T (p.L540L) and c.3888C>T (p.A1296A) variants could lead to abnormal splicing of the corresponding exons, resulting in complete skipping of exon 4 and 25% increase in the skipping of exon 18, respectively.
CONCLUSION
Synonymous variants may affect the splicing of precursor mRNA in various ways, particularly the destruction of ESE motif. This study confirmed that the c.1620C>T (p.L540L) and c.3888C>T (p.A1296A) variants can affect the mRNA splicing of the ATP7B gene, resulting in skipping of corresponding exons, which may provide a basis for genetic diagnosis and consultation of carriers.
Alternative Splicing
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Copper-Transporting ATPases/genetics*
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Enhancer Elements, Genetic
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Exons
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Gene Frequency
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Humans
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RNA, Messenger/genetics*
5.Analysis of clinical characteristics and ATP7A gene variants in a Chinese pedigree affected with Menkes disease.
Jia ZHANG ; Jing GAN ; Zuozhen YANG ; Jianjun WANG
Chinese Journal of Medical Genetics 2023;40(12):1504-1507
OBJECTIVE:
To explore the clinical characteristics and variants of ATP7A gene in a child with Menkes disease.
METHODS:
A child with Menkes disease diagnosed at the West China Second Hospital of Sichuan University and its family members in March 2022 was selected as the study subjects. Clinical manifestations and results of laboratory tests and genetic testing were summarized.
RESULTS:
The main manifestations of the child included seizures, global development delay, facial dysmorphism, sparse and curly hair, increased lactate and pyruvate, and significantly decreased cuprin. EEG showed frequent issuance of multifocal spikes, spines, polyspines (slow) and polymorphic slow waves. Multiple tortuous vascular shadows were observed on cranial MRI. Whole exome sequencing revealed that the child has harbored a hemizygous c.3076delA (p.ile1026*) variant of the ATP7A gene, which was inherited from his mother. The variant may lead to premature termination of protein translation. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted as pathogenic (PVS1+PM2+PP4).
CONCLUSION
The c.3076delA (p.Ile1026*) variant of the ATP7A gene probably underlay the Menkes disease in this child. Above finding has provided evidence for clinical diagnosis. The significantly increased lactic acid and pyruvate can be used as a reference for the diagnosis and management of Menkes disease. Microscopic abnormalities in the hair of the carriers may also facilitate their diagnosis.
Child
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Humans
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Copper-Transporting ATPases/genetics*
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East Asian People
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Menkes Kinky Hair Syndrome/genetics*
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Mutation
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Pedigree
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Peptide Fragments
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Pyruvic Acid
6.Phenotypes and ATP7B gene variants in 316 children with Wilson disease.
Zhi Kun LU ; Jing CHENG ; Si Min LI ; Yun Ting LIN ; Wen ZHANG ; Xiu Zhen LI ; Hui Ying SHENG ; Xiao Jian MAO ; Hui Fen MEI ; Rui Dan ZHENG ; Cui Li LIANG ; Min Yan JIANG ; Yong Lan HUANG ; Li LIU ; Chun Hua ZENG
Chinese Journal of Pediatrics 2022;60(4):317-322
Objectives: To summarize the clinical phenotypes and the variation spectrum of ATP7B gene in Chinese children with Wilson's disease (WD) and to investigate their significance for early diagnosis. Methods: Retrospective analysis was performed on the clinical data of 316 children diagnosed as WD in Guangzhou Women and Children's Medical Center during the period from January 2010 to June 2021. The general situations, clinical manifestations, lab test results, imaging examinations, and ATP7B gene variant characteristics were collected. The patients were divided into asymptomatic WD group and symptomatic WD group based on the presence or absence of clinical symptoms at the time that WD diagnosis was made. The χ2 test, t test or Mann-Whitney U test were used to compare the differences between groups. Results: Among the 316 children with WD, 199 were males and 117 were females, with the age of 5.4 (4.0, 7.6) years at diagnosis; 261 cases (82.6%) were asymptomatic with the age of 4.9 (3.9, 6.4) years; whereas 55 cases (17.4%) were symptomatic with the age of 9.6 (7.3, 12.0) years. The main symptoms invloved liver, kidney, nervous system, or skin damage. Of all the patients, 95.9% (303/316) had abnormal liver function at diagnosis; 98.1% (310/316) had the serum ceruloplasmin lever lower than 200 mg/L; 97.7% (302/309) had 24-hour urine copper content exceeding 40 μg; only 7.4% (23/310) had positive corneal K-F rings, 8.2% (23/281) had abnormal MRI signals in the lenticular nucleus, and all of them had symptoms of damage in liver, kidney or nervous system. Compared with the group of symptomatic WD, asymptomatic group had higher levels of serum alanine aminotransferase and lower levels ceruloplasmin and 24-hour urine copper [(208±137) vs. (72±78) U/L, (55±47) vs. (69±48) mg/L, 103 (72, 153) vs. 492 (230, 1 432) μg; t=9.98, -1.98, Z=-4.89, all P<0.001]. Among the 314 patients completing genetic sequencing, a total of 107 mutations in ATP7B gene were detected, of which 10 are novel variants, and 3 cases (1.0%) had large heterozygous deletion (exons 10 to exon 11) in ATP7B gene. The percentage of missense mutation in asymptomatic WD children was significantly higher than that in symptomatic WD (81.5% (422/518) vs. 69.1% (76/110), χ²=8.47, P<0.05). WD patients carrying homozygous variant of c.2 333G>T had significantly low levels of ceruloplasmin than those not carrying this variant ((23±5) vs. (61±48) mg/L, t=-2.34, P<0.001). Conclusions: The elevation of serum ALT is an important clue for early diagnosis of WD in children, while serum ceruloplasmin and 24-hour urine copper content are specific markers for early diagnosis of WD. In order to confirm the diagnosis of WD, it is necessary to combine the Sanger sequencing with multiplex ligation-dependent probe amplification or other testing technologies.
Ceruloplasmin/metabolism*
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Child
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Child, Preschool
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Copper/metabolism*
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Copper-Transporting ATPases/genetics*
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Female
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Hepatolenticular Degeneration/genetics*
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Humans
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Male
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Mutation
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Phenotype
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Retrospective Studies
8.Genetic analysis of a male infant with Menkes disease.
Yan HUANG ; Guanghua LIU ; Shibiao WANG ; Hui LIU ; Youfeng ZHOU
Chinese Journal of Medical Genetics 2020;37(4):479-482
OBJECTIVE:
To carry out genetic testing for a male infant suspected for Menkes disease.
METHODS:
Genomic DNA of the proband and his parents were extracted and subjected to family trio whole exome sequencing (WES). Microduplication and microdeletion of the ATP7A gene were detected by multiplex ligation-dependent probe amplification (MLPA). Suspected variants were subjected to bioinformatic analysis and verified by Sanger sequencing.
RESULTS:
The proband was found to harbor a de novo c.1870 -13T>G variation of the ATP7A gene, which may alter a splice site and affect its protein product.
CONCLUSION
The patient was diagnosed with Menkes disease due to the c.1870 -13T>G variant of the ATP7A gene. Whole exome sequencing of family trios is a powerful tool for the diagnosis of diseases with strong phenotypic heterogeneity.
Copper-Transporting ATPases
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genetics
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Genetic Testing
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Humans
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Infant
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Male
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Menkes Kinky Hair Syndrome
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genetics
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Multiplex Polymerase Chain Reaction
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Mutation
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Whole Exome Sequencing
9.Clinical and genetic analysis of three children with Menkes disease due to variants of ATP7A gene.
Zebing WANG ; Qiaomei CHEN ; You WANG ; Ling LIU ; Chengyan LI
Chinese Journal of Medical Genetics 2023;40(6):668-673
OBJECTIVE:
To explore the clinical characteristics and genetic etiology of three children with Menkes disease.
METHODS:
Three children who had presented at the Children's Medical Center, the Affiliated Hospital of Guangdong Medical University from January 2020 to July 2022 were selected as the study subjects. Clinical data of the children were reviewed. Genomic DNA was extracted from peripheral blood samples of the children, their parents and sister of child 1. Whole exome sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing, copy number variation sequencing (CNV-seq), and bioinformatic analysis.
RESULTS:
Child 1 was a 1-year-and-4-month male, and children 2 and 3 were monozygotic twin males aged 1-year-and-10-month. The clinical manifestations of the three children have included developmental delay and seizures. WES showed that child 1 has harbored a c.3294+1G>A variant of the ATP7A gene. Sanger sequencing confirmed that his parents and sister did not carry the same variant, suggesting that it was de novo. Children 2 and 3 had carried a c.77266650_77267178del copy number variation. CNV-seq results showed that their mother has carried the same variant. By searching the HGMD, OMIM and ClinVar databases, the c.3294+1G>A was known to be pathogenic. No carrier frequency has been recorded in the 1000 Genomes, ESP, ExAC and gnomAD databases. Based on the Standards and Guidelines for the Interpretation of Sequence Variants: A Joint Consensus Recommendation of the American College of Medical Genetics and Genomics (ACMG), the ATP7A gene c.3294+1G>A variant was predicted to be pathogenic. The c.77266650_77267178del variant has involved exons 8 to 9 of the ATP7A gene. ClinGen online system score for it was 1.8, which was also considered to be pathogenic.
CONCLUSION
The c.3294+1G>A and c.77266650_ 77267178del variants of the ATP7A gene probably underlay the Menkes disease in the three children. Above finding has enriched the mutational spectrum of Menkes disease and provided a basis for clinical diagnosis and genetic counseling.
Humans
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Male
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Computational Biology
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Copper-Transporting ATPases/genetics*
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DNA Copy Number Variations
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Exons
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Menkes Kinky Hair Syndrome/genetics*
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Mutation
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Peptide Fragments
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Seizures
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Infant