Clinical and genetic analysis of three children with Menkes disease due to variants of ATP7A gene / 中华医学遗传学杂志

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.

Analysis of clinical phenotypes and ATP7B gene variants in 75 children patients with Wilson' s disease / 中华医学遗传学杂志

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.

Management of hepatolenticular degeneration during pregnancy / 中华肝脏病杂志

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.

Phenotypes and ATP7B gene variants in 316 children with Wilson disease / 中华儿科杂志

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.

Pedigree study and analysis of ATP7A gene variants in three children with Menkes disease / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for three children with Menkes disease.@*METHODS@#The patients were subjected to next-generation sequencing (NGS) to detect potential variants of the ATP7A gene. Suspected variants were verified by Sanger sequencing of their family members and 200 healthy individuals. Multiplex ligation-dependent probe amplification (MLPA) was also carried out to detect potential deletions in their family members and 20 healthy individuals.@*RESULTS@#Variants of the ATP7A gene were detected in all of the three families, including a novel c.1465A>T nonsense variant in family 1, a novel c.3039_3043del frame-shifting variant in family 2, and deletion of exons 3 to 23 in family 3, which was reported previously. Based on the standards and guidelines of American College of Medical Genetics and Genomics, the c.1465A>T and c.3039_3043del variants of ATP7A gene were predicted to be likely pathogenic (PVS1+PM2).@*CONCLUSION@#Variants of the ATP7A gene may underlay the Menkes disease in the three children. Above findings have facilitated clinical diagnosis and enriched the spectrum of genetic variants of Menkes disease.

Genetic analysis of a male infant with Menkes disease / 中华医学遗传学杂志

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.

CtpB is a plasma membrane copper (I) transporting P-type ATPase of Mycobacterium tuberculosis

BACKGROUND: The intracellular concentration of heavy-metal cations, such as copper, nickel, and zinc is pivotal for the mycobacterial response to the hostile environment inside macrophages. To date, copper transport mediated by P-type ATPases across the mycobacterial plasma membrane has not been sufficiently explored. RESULTS: In this work, the ATPase activity of the putative Mycobacterium tuberculosis P1B-type ATPase CtpB was associated with copper (I) transport from mycobacterial cells. Although CtpB heterologously expressed in M. smegmatis induced tolerance to toxic concentrations of Cu2+ and a metal preference for Cu+, the disruption of ctpB in M. tuberculosis cells did not promote impaired cell growth or heavy-metal accumulation in whole mutant cells in cultures under high doses of copper. In addition, the Cu+ ATPase activity of CtpB embedded in the plasma mem-brane showed features of high affinity/slow turnover ATPases, with enzymatic parametersKM 0.19 ± 0.04 µM and Vmax 2.29 ± 0.10 nmol/mg min. In contrast, the ctpB gene transcription was activated in cells under culture conditions that mimicked the hostile intraphagosomal environment, such as hypoxia, nitrosative and oxidative stress, but not under high doses of copper. CONCLUSIONS: The overall results suggest that M. tuberculosis CtpB is associated with Cu+ transport from mycobacterial cells possibly playing a role different from copper detoxification.

Synonymous variants of the ATP7B gene may cause abnormal splicing of mRNA by affecting the exonic splicing enhancers / 中华医学遗传学杂志

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 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.

Enfermedad de Wilson: reporte de caso / Wilson ́s disease: a case report

La enfermedad de Wilson es una condición genética autosómica recesiva poco frecuente. Se ha identificado el gen ATP7B como el que codifica la proteína transportadora de cobre y su deficiencia lleva al acúmulo del metal en el cerebro, hígado y otros órganos vitales. Su diagnóstico clínico precoz es esencial para mejorar la calidad de vida del paciente. A continuación, se presenta el caso de un paciente de 20 años, masculino, con un cuadro clínico de 2 años de evolución de desinhibición, impulsividad, anartria y apraxia de la marcha, movimientos distónicos faciales y en 4 extremidades. Al examen físico se evidenció el anillo de Kayser Flescher a nivel ocular. En Resonancia Magnética Encefálica hiperintensidad en ganglios de la base y mesencéfalo en T2. Ceruloplasmina en suero 4.08 mg/dL. Cobre sérico 26.03ug/dL y cobre en orina de 24 horas 224.30ug/ 24h. Se confirma el diagnóstico de Enfermedad de Wilson, tratándose con D- Penicilamina, evidenciándose una evolución adecuada, con mejoría notable del cuadro neurológico. El tratamiento precoz permite una evolución favorable temprana del paciente, disminuyendo las secuelas neurológicas secundarias a la enfermedad; de ahí la importancia del reporte del presente caso.(AU)

BackgroundWilson's disease is a rare autosomal recessive genetic condition. The ATP7B gene has been identified as the one that encodes the copper transport protein and its deficiency leads to the accumulation of metal in the brain, liver and other vital organs. Your early clinical diagnosis is essential to improve the quality of life of the patient. Following we present the clinical case of a 20-year-old male patient who since 2 years ago, presented disinhibition, impulsivity, anartria and gait apraxia, facial dystonic movements and in extremities. To the physical exam, Kayser Flescher ring was present. In Brain Magnetic Resonance hyperintensity in Basal Ganglia and Midbrain. Serum Ceruloplasmin 4.08. Serum Copper 26.03. Urinary Cupper 224.30. The diagnosis of Wilson's disease is confirmed, treating with D-Penicillamine, evidencing an adequate evolution, with notable improvement of the neurological symptoms. Early treatment allows a favorable early evolution of the patient, reducing the neurological sequelae secondary to the disease; so that the importance of the report of this case.(AU)

Identification of ATP7B gene variant by combined use of Sanger sequencing, array CGH and quantitative PCR / 中华医学遗传学杂志

OBJECTIVE@#To identify the type and origin of ATP7B gene mutation in a family affected with Wilson disease by combined use of multiple methods.@*METHODS@#Peripheral blood samples were collected from the proband, her parents and her brother. Sanger sequencing were used to detect point mutation and small deletion/insertion of the 21 exons and flanking sequences of the ATP7B gene in all family members. Array-based comparative genomic hybridization (aCGH) was performed to identify copy number variations (CNVs) of the ATP7B gene in the proband. The result was validated by quantitative PCR (qPCR) in other 3 members.@*RESULTS@#Sanger sequencing indicated that the proband carried a heterozygous variation c.2668G>A (p.V890M) derived from her mother. In addition, 5 common SNPs were detected in her mother, three of which were also identified in her father and brother. The 5 SNPs in the proband were of the wide type. aCGH analysis demonstrated that the proband was heterozygous for a 4 kb deletion, which encompassed exons 2 and 3 of the ATP7B gene and 2 SNPs. qPCR showed that the copy number in her father and brother was about half of the control, indicating heterozygous loss of exons 2 and 3.@*CONCLUSION@#The combined Sanger sequencing, array CGH and qPCR has identified a novel CNV involving the ATP7B gene. The strategy can improve the diagnostic rate for hereditary or rare diseases.

Analysis of clinical features and genetic mutations in a Chinese family affected with Menkes disease / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To delineate the clinical features and potential mutation of the ATP7A gene in a family affected with Menkes disease.</p><p><b>METHODS</b>Clinical data of a patient and his family members were analyzed. Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) assays were performed to detect the mutation of the ATP7A gene.</p><p><b>RESULTS</b>The patient was admitted at the age of 5 months due to severe epilepsy and marked delayed psychomotor development. Significantly light complexion, pudgy cheeks and sparse fuzzy wooly hair were noted. Cranial magnetic resonance imaging and angiography revealed cortical atrophy, leukoencephalopathy and circuitous of intracranial vessels. The plasma ceruloplasmin was decreased. MLPA has identified a deletion spanning exons 8 to 12 of the ATP7A gene. His mother was found to be a heterozygous carrier of the same mutation.</p><p><b>CONCLUSION</b>The clinical features and a novel mutation of the ATP7A gene of the family have been delineated.</p>

Mutation analysis of 35 Wilson's disease pedigrees / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze the features of genetic mutations underlying Wilson's disease and provide prenatal and presymptomatic diagnosis.</p><p><b>METHODS</b>For 35 pedigrees affected with the disease, the exons and exon-intron boundaries of the ATP7B gene were amplified with polymerase chain reaction and subjected to Sanger sequencing. After the genotypes of parents of the probands were determined, prenatal diagnosis were performed through chorionic villus sampling.</p><p><b>RESULTS</b>The overall rate for mutation detection was 92.9%. A total of 24 distinct mutations were detected, which included 7 novel mutations, i.e., c.3871G>A(p.A1291T), c.2593_2594insGTCA, c.2790_2792delCAT, c.3661_3663delGGG, c.3700delG, c.4094_4097delCTGT, and IVS6+1G>A. Three mutations, including R778L (c.2333G>T)(45.7%), A874V (c.2621C>T)(7.1%) and P992L (c.2975C>T)(7.1%), were relatively common. Two presymptomatic patients were detected through familial screening, for whom treatment was initiated. Prenatal genetic diagnosis has verified three healthy fetuses and one carrier.</p><p><b>CONCLUSION</b>In this study the most popular mutation ofATP7B gene is R778L and 7 novel mutations have been identified in this gene. For pedigrees of Wilson's disease, genetic counseling in addition with prenatal and presymptomatic diagnosis should be provided through Sanger sequencing and haplotype analysis.</p>

Currently Clinical Views on Genetics of Wilson's Disease / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>The objective of this study was to review the research on clinical genetics of Wilson's disease (WD).</p><p><b>DATA SOURCES</b>We 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.</p><p><b>STUDY SELECTION</b>Publications about the ATP7B gene and protein function associated with clinical features were selected.</p><p><b>RESULTS</b>Wilson'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.</p><p><b>CONCLUSIONS</b>Clinical 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.</p>

A young boy with elevated aminotransferases in physical examination--Two novel missense mutations associated with Wilson's disease were found / 中国当代儿科杂志

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.

Whole blood allele-specific PCR, a simple method to detect four ATP7B gene mutations in Wilson disease / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To 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.</p><p><b>METHODS</b>Four 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.</p><p><b>RESULTS</b>The 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%.</p><p><b>CONCLUSION</b>Our 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.</p>

Clinical and ATP7A gene analysis of three infants with Menkes disease and prenatal diagnosis for a fetus at risk / 中国当代儿科杂志

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.

Clinical and genetic study of Wilson's disease in affected twins and siblings / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the clinical and genetic characteristics of twins and siblings affected with Wilson's disease (WD).</p><p><b>METHODS</b>Clinical data and blood samples were collected from the subjects after informed consent was obtained. Genomic DNA was extracted and potential mutations in the exons in ATP7B gene were detected with PCR-DNA sequencing. Short tandem repeat (STR) genotyping was performed to determine the zygosity of the twins.</p><p><b>RESULTS</b>The 5 pairs of twins have all met the diagnostic criteria for WD. STR genotyping has confirmed that 4 pairs were monozygotic twins. 3 pairs of twins had an onset with liver symptoms, the other 2 had an onset with brain symptoms. ATP7B gene mutations were detected in 4 pairs of twins, which have all located in exons 8 and 13. A heterozygous p.R778W mutation in exon 8 and homozygous p.P992L mutation in exon 13 were detected in all patients from one family, whose parents have carried a heterozygous p.R778W mutation and p.P992L heterozygous mutation, respectively, which suggested loss of heterozygosity (LOH). In one family, no mutation was detected in all exons of the ATP7B gene in the patients and their parents. For a triplet, one female was with definite WD and brain symptoms at the onset, one male had subclinical type with WD, whilst another female was completely normal. The triplets and their mother have all carried a p.P992L heterozygous mutation .</p><p><b>CONCLUSION</b>Above results have confirmed an important role for genetic factors in the pathogenesis of WD. In addition to point mutations, LOH is also involved in the pathogenesis for WD.</p>

Establishment of hepatic and neural differentiation platforms of Wilson's disease specific induced pluripotent stem cells

The combination of disease-specific human induced pluripotent stem cells (iPSC) and directed cell differentiation offers an ideal platform for modeling and studying many inherited human diseases. Wilson's disease (WD) is a monogenic disorder of toxic copper accumulation caused by pathologic mutations of the ATP7B gene. WD affects multiple organs with primary manifestations in the liver and central nervous system (CNS). In order to better investigate the cellular pathogenesis of WD and to develop novel therapies against various WD syndromes, we sought to establish a comprehensive platform to differentiate WD patient iPSC into both hepatic and neural lineages. Here we report the generation of patient iPSC bearing a Caucasian population hotspot mutation of ATP7B. Combining with directed cell differentiation strategies, we successfully differentiated WD iPSC into hepatocyte-like cells, neural stem cells and neurons. Gene expression analysis and cDNA sequencing confirmed the expression of the mutant ATP7B gene in all differentiated cells. Hence we established a platform for studying both hepatic and neural abnormalities of WD, which may provide a new tool for tissue-specific disease modeling and drug screening in the future.

Doença de Wilson em crianças e adolescentes: como fazer diagnóstico precoce / Wilson's disease in children and adolescent: a key to an early diagnosis

A doença de Wilson é uma desordem autossômica recessiva do metabolismo do cobre, que leva à impregnação desse metal em diversos tecidos como o fígado, cérebro, córnea e rins. Tem prevalência de 1:40.000 e evolui de forma progressiva e fatal se não tratada. Seu diagnóstico depende de suspeição clínica e exames laboratoriais, podendo ser difícil nos pacientes assintomáticos ou com insuficiência hepática grave. A tríade clássica de apresentação é hepática, neurológica e oftalmológica. Na criança, a forma de apresentação mais comum é a hepática (aguda ou crônica). Os critérios diagnósticos são baseados na presença de ceruloplasmina baixa, cobre em urina de 24 horas e cobre livre elevados e avaliação oftalmológica à procura do anel de Kayser-Fleischer. O tratamento medicamentoso deve ser instituído o quanto antes, de forma a evitaremse as lesões teciduais do excesso de cobre, daí a grande importância do diagnóstico precoce. A droga de escolha é a D-penicilamina, mas é necessário o monitoramento de seus possíveis efeitos colaterais e eventuais pioras do quadro neuropsiquiátrico. Existem outras drogas, como a trientina, tetratiomolibdato e o zinco, que também têm efeito na redução do cobre orgânico. (AU)

Wilson disease is an authossomal recessive disorder of copper metabolism that leads to the impregnation of the metal in different tissues such as the liver, brain, cornea and kidneys. There is a prevalence of 1:40,000 and evolution is progressive and fatal if untreated. The diagnosis depends on clinical suspicion and laboratory tests, and may be difficult in situations such as the asymptomatic patients or with severe liver insufficiency. The classic triad presentation is the hepatic, neurological and ophthalmologic disease. In children, the most common is the hepatic (acute or chronic). The diagnosis criteria are based on the presence of low ceruloplasmine, elevated copper in 24-hour urine and high seric copper and ophthalmologic evaluation in search of Kayser Fleischer ring. The medication treatment must be established as soon as possible so as to prevent tissue lesions due to copper excess, hence the great importance of early diagnosis. The drug choice is the D-penicilamin, with careful monitoring of side effects and attention for occasional worsening of the neuropsychiatric state. There are other drugs as trientine, tetratiomolibdato and zinc that also have an effect on the reduction of organic copper. (AU)

Rapid detection of common ATP7B mutations in Wilson disease by high resolution melting analysis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the most prevalent mutations, R778L and P992L of ATP8B gene, in Chinese Wilson disease(WD) patients by high resolution melting (HRM) analysis after polymerase chain reaction (PCR).</p><p><b>METHODS</b>Genomic DNA was extracted from peripheral blood samples obtained from 30 cases of WD by the standard phenol/chloroform method. DNA fragments encompassing ATP7B exons 8 and 13 were produced by PCR amplification. The amplicons containing the R778L or P992L mutations were then generated by nested PCR. The nested PCR products were subjected to HRM analysis using the HR-1 instrument. Mutations detected in HRM analysis were verified by restriction analysis using restriction enzyme (MspI or AluI or AfaI) or DNA sequencing.</p><p><b>RESULTS</b>HRM analysis of the fragments encompassing ATP7B exon 8 showed four curve patterns. Subsequent restriction analysis and DNA sequencing proved that the four different curves represent four different genotypes: the wild type, the R778L/R778L homozygote, the R778L heterozygote, and the R778L/752.33delG compound heterozygote. Three HRM curve patterns were observed for the fragments encompassing ATP7B exon 13, representing the wild type, the P992L heterozygote, and the P992L/S975Y compound heterozygote. In our studied samples, allele frequencies of the R778L, P992L and S975Y mutations were 25%, 15% and 1.67%, respectively.</p><p><b>CONCLUSION</b>HRM analysis is a simple, accurate and sensitive approach for rapid detection of the ATP7B mutations and could be used as an optimized method for genetic testing in WD.</p>