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 ; Copper-Transporting ATPases/genetics* ; Female ; Hepatolenticular Degeneration/therapy* ; Humans ; Mutation ; Pregnancy

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

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 ; Copper-Transporting ATPases/genetics* ; Enhancer Elements, Genetic ; Exons ; Gene Frequency ; Humans ; RNA, Messenger/genetics*

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* ; Genotype ; Hepatolenticular Degeneration/genetics* ; Humans ; Mutation ; Phenotype ; Retrospective Studies

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 ; Humans ; Copper-Transporting ATPases/genetics* ; East Asian People ; Menkes Kinky Hair Syndrome/genetics* ; Mutation ; Pedigree ; Peptide Fragments ; Pyruvic Acid

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* ; Child ; Child, Preschool ; Copper/metabolism* ; Copper-Transporting ATPases/genetics* ; Female ; Hepatolenticular Degeneration/genetics* ; Humans ; Male ; Mutation ; Phenotype ; Retrospective Studies

Menkes disease is a rare X-linked recessive disorder characterized by multi-systemic disorder of copper deficiency caused by ATP7A gene mutation. In this study, the clinical and laboratory features of three patients with Menkes disease were analyzed. Prenatal diagnosis had been performed for a fetus of a family. Three patients were admitted at the age of 8-9 months due to severe epilepsies and marked delayed psychomotor development. Significantly light complexion, pudgy cheeks and sparse fuzzy wooly hair were observed. On their cranial MR imaging, cortical atrophy, leukoencephalopathy, basal ganglia damage and tormesity of the intracranial vessels were found. Their plasma ceruloplasmin decreased to 70.2, 73.5 and 81 mg/L, significantly lower than normal range (210-530 mg/L). c.3914A>G (p. D1305G) was detected on ATP7A gene of case 1 and 2. A novel mutation, c.3265G>T (p.G1089X) was found in case 3. Both of them were firstly found in Chinese patients of Menkes disease. The mother of case 1 was tested at 20 weeks of pregnancy. Karyotype and ATP7A gene studies of the amniocytes were performed for the prenatal diagnosis of her fetus. Normal male karyotypes without c.3914A>G mutation on ATP7A gene was showed. Postnatal genetic analysis and normal development confirmed the prenatal diagnosis.
Adenosine Triphosphatases ; genetics ; Cation Transport Proteins ; genetics ; Copper-transporting ATPases ; Humans ; Infant ; Male ; Menkes Kinky Hair Syndrome ; diagnosis ; genetics ; Mutation ; Prenatal Diagnosis

OBJECTIVETo establish a simple method to detect four ATP7B gene mutations in Wilson disease using allele-specific PCR(AS-PCR) with whole blood polymerase chain reaction.

METHODSFour allele-specific PCR primers specific for the mutations(G2333T, C2850T, G2855A, G2975T) were designed, and PCR was optimized to screen the whole blood samples. The amplified gene products with mutation were separated with agarose gel electrophoresis to detect the pattern of point mutation and allele types. Exons 8, 12 and 13 of the ATP7B gene were amplified with PCR, and the amplification products were sequenced to confirm the mutation.

RESULTSThe detection of four ATP7B gene mutations by AS-PCR with whole blood was accomplished with 100% accuracy. In the 27 healthy subjects, the mutation rate of G2855A was 51.8%. No mutation was detected for G2333T, C2850T and G2975T. Among the 22 patients, 11 were mutated for G2333T, C2850T or G2975T. The mutation rate was therefore 50%.

CONCLUSIONOur experiment has established an AS-PCR based method for detecting four ATP7B gene mutations using whole blood samples, which has provided a simple and effective means for the early diagnosis of Wilson disease. This method is rapid, convenient, accurate and economical for detecting point mutations of the ATP7B gene.

Adenosine Triphosphatases ; genetics ; Adolescent ; Adult ; Alleles ; Cation Transport Proteins ; genetics ; Child ; Copper-transporting ATPases ; Female ; Hepatolenticular Degeneration ; genetics ; Humans ; Male ; Middle Aged ; Mutation ; Polymerase Chain Reaction ; methods

Adenosine Triphosphatases ; genetics ; Cation Transport Proteins ; genetics ; Copper-transporting ATPases ; Gene Deletion ; Humans ; Infant ; Male ; Menkes Kinky Hair Syndrome ; genetics ; Polymorphism, Single Nucleotide

A 3-year-old boy had abnormal liver function, which was found in physical examination, for 5 months before admission. He had no symptoms such as anorexia, poor appetite, and jaundice, had normal growth and development, and showed no hepatosplenomegaly. Laboratory examination revealed significantly reduced ceruloplasmin (35 mg/L), as well as negative hepatotropic virus, cytomegalovirus, and Epstein-Barr virus. There were normal muscle enzymes, blood glucose, and blood ammonia and negative liver-specific autoantibodies. The boy had negative K-F ring and normal 24-hour urine copper (0.56 μmol/L). The ATP7B gene testing for the boy, his sister, and their parents detected two novel missense mutations in the boy and his sister, i.e., compound heterozygous mutations in exon 7 (c.2075T>C, p.L692P) and exon 13 (c.3044T>C, p.L1015P), which were inherited from their father and mother, respectively. Wilson's disease was confirmed by genetic diagnosis in the boy and his sister. The boy and his sister were given a low-copper diet. The boy was administered with penicillamine for decoppering and zinc supplement against copper uptake. His sister received zinc supplement alone because no clinical symptoms were observed. The boy showed normal liver function in the reexamination after 3 months of treatment.
Adenosine Triphosphatases ; genetics ; Alanine Transaminase ; blood ; Cation Transport Proteins ; genetics ; Child, Preschool ; Copper-transporting ATPases ; Female ; Hepatolenticular Degeneration ; genetics ; physiopathology ; Humans ; Liver ; physiopathology ; Male ; Mutation, Missense ; Physical Examination