ABSTRACTBackgroundChromosome 3q29 duplication syndrome is a rare chromosomal disorder with a frequency of 1:5000 in patients with a neurodevelopmental phenotype. The syndrome is characterized by phenotypic polymorphism and reduced penetrance.MethodsPatients were investigated by performing a cytogenetic analysis of GTG‐banded metaphases, aCGH with the SurePrint G3 Human CGH Microarray 8×60K, qPCR, FISH, and WES.ResultsHere, we report five new patients with atypical duplications overlapping with the 3q29 duplication syndrome region and no other genetic findings. In two patients, duplications were found in the single BDH1 gene, a candidate gene for the 3q29 duplication phenotype. For the first time, we delineated and described the smallest minimal critical region, including the single BDH1 gene; in our patients, this region was associated with ASD, heart defects, biliary tract dysfunction, and obesity. The frequencies of the pathological phenotypes in duplication carriers reported in the literature were calculated and compared with those in patients with 3q29 deletions. Most of the phenotypes were observed in both groups but were significantly less common among individuals with 3q29 duplications. Mirrored phenotypes in patients with duplications and deletions included overweight and weight deficit. Schizophrenia, generalized anxiety disorder, and recurrent ear infections were unique phenotypes of patients carrying deletions.ConclusionChromosome 3q29 duplication syndrome is characterized by a complex genetic architecture and clinical polymorphism.

BACKGROUND:The X chromosome is enriched with genes related to brain development, and the hemizygous state of these genes in men causes some difficulties in the clinical interpretation of copy number variations (CNVs). In this study, we present data on the frequency and spectrum of CNVs on the X chromosome in a cohort of patients with neurodevelopmental disorders (NDDs). METHODS:Chromosomal microarray analysis was performed for 1175 patients with NDDs. CNVs were confirmed by real-time quantitative PCR. X chromosome inactivation was analysed by methyl-sensitive PCR. To determine the pathogenic significance of the CNVs, several criteria, including the origin (inherited or de novo), variant type (microdeletion or microduplication), and X chromosome inactivation pattern in asymptomatic and symptomatic carriers, were considered. Additionally, the spectrum, size and molecular bases of copy number changes in genes or gene regions involved in the development of the pathological phenotype in each patient were considered. RESULTS:CNVs on the X chromosome were identified in 33 patients (2.8%). Duplications and triplications (27 cases) were four times more common than deletions (6 cases). In 74% of patients, CNVs were of maternal origin; in 10% they were of paternal origin; and in 16% they arose de novo. The frequency of skewed X inactivation among family members who were healthy carriers of pathogenic and likely pathogenic CNVs and variants of uncertain significance (VUSs) on the X chromosome was 23%. For the first time, we reported several CNVs, including a pathogenic microdeletion at Xq26.1q26.2 involving the ARHGAP36 gene and a microduplication at Xp22.2 involving the OFD1 gene, CONCLUSIONS: This study expands on the frequency and spectrum of CNVs in patients with NDDs. Pathogenic variants on the X chromosome were present in 15% of cases, LP in 12%, VUS in 57%, and LB in 16% of cases. Previously unreported CNVs aid in the identification of new structural variants and genes associated with X-linked intellectual disability. We propose to consider the X-chromosome inactivation status when assessing the pathogenetic significance of CNVs using the ACMG algorithm (American College of Medical Genetics).

We report a novel variant in the MACF1 gene that caused a congenital brain anomaly (lissencephaly, brainstem hypoplasia, and agenesis of the corpus callosum) in a patient with severe neurodevelopmental delay and drug-resistant epilepsy. The patient was nonresponsive, nonverbal, and nonambulatory and experienced daily generalized myoclonic seizures, generalized muscle weakness, dysphagia, and faecal and urinary incontinence. Whole-exome sequencing revealed a missense heterozygous MACF1 variant, c.21878A > G (p.Asp7293Gly). The de novo origin of the variant was confirmed by trio Sanger sequencing. The variant was not reported previously in the gnomAD, ExAC, and 1000 Genomes databases. Our report expands the genetic heterogeneity of a rare type of lissencephaly.

Relevance. The problem of diagnosing hereditary neuromuscular diseases is one of the most difficult in the medical specialists’ practice. Molecular genetic diagnostics is one of the fundamental aspects in the classification and subsequent approaches to the treatment and prevention of hereditary diseases. Pathogenic variants identification leads to the formation of separate subtypes and phenotypically identical diseases syndromes. This review examines modern diagnostic methods and algorithmization of patients with neuromuscular diseases. Despite enormous research and clinical efforts, the molecular causes remain unknown for almost half of patients with neuromuscular diseases due to genetic heterogeneity and molecular diagnostics based on a gene-by-gene approach. Next-generation sequencing (NGS) is an effective and cost-effective strategy for accelerating patient diagnosis. However, the diagnostic value of conducting and prescribing whole- exome or whole- genome sequencing is largely dependent on the clinical picture of the disease and the professional competence of the doctor. Hereditary neuromuscular diseases have similar initial symptoms, and molecular genetic diagnostics can pinpoint the cause and pathogenesis of the observed disorders in the patient. Conclusion . The molecular diagnostics algorithm is based on sequential analysis, starting with the search for the most common pathogenic variants using inexpensive and rapid methods, and progressing to the search for rare, previously undescribed pathogenic variants using whole-g enome/whole-exome studies. The phasing allows science and medicine to uncover previously unknown causes of severe disease in patients with neuromuscular diseases, which often leading to disability or premature death. Earlier genetic diagnosis should provide more effective treatment of the disease and better genetic counseling for families and will also allow access to pathogenetic therapy for neuromuscular diseases.

Pallister-Killian syndrome (PKS) is a rare inherited disease with multiple congenital anomalies, profound intellectual disability, and the presence in the karyotype of sSMC - i(12)(p10). The frequency of PKS may be underestimated due to problems with cytogenetic diagnosis caused by tissue-specific mosaicism and usually a low percentage of peripheral blood cells containing sSMC. Such tissue-specific mosaicism also complicates a detailed analysis of the sSMC, which, along with the assessment of mosaicism in different tissues, is an important part of cytogenetic diagnosis in PKS. Unfortunately, a full-fledged diagnosis in PKS is either practically impossible or complicated. On the one hand, this is due to problems with the biopsy of various tissues (skin biopsy with fibroblast culture is most often used in practice); on the other - a low percentage of dividing peripheral blood cells containing sSMC, which often significantly complicates the analysis of its composition and organization. In the present study, a detailed analysis of sSMC was carried out in a patient with a characteristic clinical picture of PKS. A relatively high percentage of peripheral blood cells with sSMC (50%) made it possible to perform a detailed molecular cytogenetic analysis of de novo sSMC using chromosomal in situ suppression hybridization (CISS-hybridization), multicolor FISH (mFISH), multicolor chromosome banding (MCB), array CGH (aCGH), and quantitative real-time PCR (qPCR), and short tandem repeat (STR) - analysis. As a result, it was found that the sSMC is not a typical PKS derivative of chromosome 12. In contrast to the classical i(12)(p10) for PKS, the patient’s cells contained an acrocentric chromosome consisting of 12p material. Clusters of telomeric repeats were found at the both ends of the sSMC. Furthemore, the results of aCGH and qPCR indicate the presence of interstitial 8.9 Mb duplication at 12p13.1-p12.1 within the sSMC, which leads to different representations of DNA from different segments of 12p within cells containing sSMC. The obtained data raise the question of the instability of the sSMC and, as a consequence, the possible presence of additional rearrangements, which, in traditional cytogenetic analysis of patients with PKS, are usually described as i(12)(p10).

The ATOX1 (Antioxidant Protein 1) is a human copper metal chaperone that plays an important role in cellular copper homeostasis. The protein is responsible for cytosolic copper absorption from CTR1 (copper transporter 1) and transport to the copper pumps in the Trans Golgi network to the ATP7A and ATP7B proteins. This review collects data on the antioxidant role of ATOX1, the gene role’s in the angiogenesis regulation and cancer cell proliferation, and its role in the pathogenesis of copper-induced diseases—Wilson–Konovalov disease and Menkes disease.

Introduction The deductive method: from karyotyping to aCGH and WES is an important aspect in the diagnosis and search for the causes of intellectual disability due to congenital brain anomalies. There is recommendation to exclude the presence of CNV or monogenic variants for patients with a normal karyotype, but with a clinical picture of syndromic disease. Objectives Improvement of diagnosis of intellectual disability. Methods aCGH with 60K Agilent microarrays, WES with SureSelect Human All Exon V8 Results Pathogenic or potentially pathogenic CNVs were excluded previously by aCGH for 10 families (total 32 people, 2 families had 2 children) with intellectual disability and congenital brain anomalies (for example, polymicrogyria, pachygyria, lissencephaly). The WES identified candidate variants for all families that can lead to impaired neurodevelopment, including 3 pathogenic variants in 3 families, 3 likely pathogenic in three other families, and 10 variants with uncertain clinical significance for 4 families. Almost all of these variants were identified de novo, except for one family, where the proband has been a compound heterozygous for two variants in the RELN gene. The first case of pathogenic mutation de novo was detected in a girl with agenesis of the corpus callosum. It was a missense mutation DYNC1H1 (NM_001376.5): c.4868G>A (p.Arg1623Gln), which leads to impaired intellectual development in autosomal dominant type 13 (OMIM 614563). The second variant was detected in a boy with corpus callosum agenesis, pontine hypogenesis, pachygyria in the frontal lobes. It was a missense variant MACF1 (ENST00000567887.5): c.21989A>G(p.Asp7330Gly), which leads to lissencephaly 9 with complex brainstem malformation (OMIM 614563). The third variant was found in a girl with epilepsy and impaired myelination of the white matter of the parietal-occipital areas of the cerebral hemispheres. It was a missense variant CDKL5 (NM_001323289.2):c.404-1G>A that leads to developmental and epileptic encephalopathy 2 (OMIM 300672). Conclusions Sixteen candidate variants potentially responsible for mental health were reported in this study. Most of these variants were missense changes in genes. All except one anomalies arisen de novo. Trio-based WES has been shown to be an important step in making a genetic diagnosis if other chromosomal and subchromosomal abnormalities had been excluded. The clinical description of the patient is the most important step for the correct interpretation of WES results, which allows to establish the exact genetic cause of the disease if several variants with unclear clinical significance were previously identified. This study was supported by the Russian Science Foundation, grant 21-65-00017, https://rscf.ru/project/21-65-00017/ Disclosure of Interest None Declared

Pregnancy loss is often caused by chromosomal abnormalities of the conceptus. The prevalence of these abnormalities and the allocation of (ab)normal cells in embryonic and placental lineages during intrauterine development remain elusive. In this study, we analyzed 1,745 spontaneous pregnancy losses and found that roughly half (50.4%) of the products of conception (POCs) were karyotypically abnormal, with maternal and paternal age independently contributing to the increased genomic aberration rate. We applied genome haplarithmisis to a subset of 94 pregnancy losses with normal parental and POC karyotypes. Genotyping of parental DNA as well as POC extra-embryonic mesoderm and chorionic villi DNA, representing embryonic and trophoblastic tissues, enabled characterization of the genomic landscape of both lineages. Of these pregnancy losses, 35.1% had chromosomal aberrations not previously detected by karyotyping, increasing the rate of aberrations of pregnancy losses to 67.8% by extrapolation. In contrast to viable pregnancies where mosaic chromosomal abnormalities are often restricted to chorionic villi, such as confined placental mosaicism, we found a higher degree of mosaic chromosomal imbalances in extra-embryonic mesoderm rather than chorionic villi. Our results stress the importance of scrutinizing the full allelic architecture of genomic abnormalities in pregnancy loss to improve clinical management and basic research of this devastating condition.

Introduction aCGH determines pathogenic copy number variations (CNVs) in about 10% of patients with intellectual disability (ID). In another 20% of patients, probably pathogenic CNVs or variants with uncertain clinical significance are detected. It may be variants that do not fully explain the patient’s symptoms, aberrations with reduced penetrance or inherited from healthy parents. The use of a sequencing method for such cases is advisable. Objectives Improvement of diagnosis of intellectual disability. Methods aCGH with 60K Agilent microarrays, qPCR, targeted sequencing, whole exome sequencing (WES). Results Six patients with ID and inherited deletions/duplications detected by aCGH and their parents if available were further examined by sequencing. Four patients had maternal CNVs: (1) del1q41 ( SPATA17, LINC00210, RRP15 ), (2) del7q35 ( TCAF2 , exon 8), (3) dup8p22p21.3 ( PSD3, exons 1-11), and (4) del12p11.1 ( SYT10, exons 1-2). Two patients had paternal CNVs: (5) dup1q44 ( SMYD3 , exons 2-5) and (6) del15q11.2 ( TUBGCP5, CYFIP1, NIPA1, NIPA2, LOC283683 ). The severe phenotype of patient (5) with dup1q44 could not be explained by the paternally inherited disruption of the single SMYD3 gene. WES determined probably pathogenic SNV in the MID1 gene associated with Opitz GBBB syndrome (OMIM 300000), which corresponds better to the patient’s phenotype and is likely to be the cause of the disease. Although del1q41 is included in the region of chromosome 1q41-q42 deletion syndrome (OMIM 612530) the phenotype of the patient (1) is much milder; WES in the patient detected two pathogenic ( MPO, MAN2C1 ) and one probably pathogenic ( ARID1B ) SNVs. In patient (6) with del15q11.2 pat WES detected additional pathogenic SNV in exon 7 of the ARSE gene. In patient (3) with dup8p22p21.3 WES determined two SNVs with uncertain significance in the KIDINS220, FOXG1 genes. No SNVs were detected by WES in patient (2) with del7q35. For patient (4) with del12p11.1 targeted SYT10 sequencing revealed no pathogenic SNVs as well. Conclusions Sometimes aCGH-analysis is sufficient to identify the causes of ID, however, in the case of detection of CNVs with uncertain clinical significance and/or inherited from healthy parents, it may be necessary to further examine the patient using sequencing methods. So, the accurate diagnosis was made by WES for one patient of eight. For another two patients the combination of CNVs and SNPs should be considered. For the last three patients the described aberrations could not explain the phenotype and whole genome sequencing may be the solution.This study was supported by the Russian Science Foundation, grant 21-65-00017, https://rscf.ru/project/21-65-00017/ Disclosure of Interest None Declared

Skewed X-chromosome inactivation (sXCI) can be a marker of lethal genetic variants on the X chromosome in a woman since sXCI modifies the pathological phenotype. The aim of this study was to search for CNVs in women with miscarriages and sXCI. XCI was assayed using the classical method based on the amplification of highly polymorphic exon 1 of the androgen receptor (AR) gene. The XCI status was analysed in 313 women with pregnancy loss and in 87 spontaneously aborted embryos with 46,XX karyotype, as well as in control groups of 135 women without pregnancy loss and 64 embryos with 46,XX karyotype from induced abortions in women who terminated a normal pregnancy. The frequency of sXCI differed significantly between women with miscarriages and women without pregnancy losses (6.3% and 2.2%, respectively; p = 0.019). To exclude primary causes of sXCI, sequencing of the XIST and XACT genes was performed. The XIST and XACT gene sequencing revealed no known pathogenic variants that could lead to sXCI. Molecular karyotyping was performed using aCGH, followed by verification of X-linked CNVs by RT-PCR and MLPA. Microdeletions at Xp11.23 and Xq24 as well as gains of Xq28 were detected in women with sXCI and pregnancy loss.

Моногенные вариации числа копий участков ДНК (CNV) у пациентов с нарушением психомоторного развития выявляются с частотой до 10%. Исход данного типа аберраций более очевиден, если затронут дозозависимый ген, ассоциированный с заболеванием. Однако патологический фенотип может формироваться в результате гемизиготизации рецессивного варианта нуклеотидной последовательности на интактном гомологе или при сочетании CNV и нуклеотидного варианта (компаундная гетерозигота). Нами разработан и апробирован для 1176 пациентов алгоритм молекулярной диагностики наследственной патологии, ассоциированной с моногенными CNV. Патогенные, вероятно патогенные и структурные хромосомные аберрации с неопределенной клинической значимостью выявлены у 478 пробандов (40,6%), в том числе моногенные CNV - у 60 пациентов (5,1%). Среди 32 моногенных аберраций, присутствие которых подтверждено методом ПЦР в реальном времени, большая часть была унаследована от здоровых родителей (23 CNV или 72%). Семи пациентам проведено секвенирование. Ни одного патогенного варианта нуклеотидной последовательности на интактном гомологе выявлено не было, однако в ряде случаев обнаружены не описанные ранее варианты неопределенного значения в генах, не вовлеченных в CNV. Single-gene copy number variations (CNVs) in patients with impaired psychomotor development are detected with a frequency of up to 10%. The outcome of this type of aberration is more obvious if a dosage-sensitive gene associated with the disease is affected. However, a pathological phenotype can also be formed as a result of hemizygotization of a recessive nucleotide sequence variant from an intact homologue or by combining CNV and a nucleotide variant (compound heterozygote). We have developed and tested for 1176 patients an algorithm for the molecular diagnosis of hereditary pathology associated with single-gene CNV. Pathogenic, likely pathogenic and structural chromosomal aberrations with uncertain clinical significance were detected in 478 probands (40.6%), including monogenic CNV in 60 patients (5.1%). Among 32 single-gene aberrations, the presence of which was confirmed by real-time PCR, most were inherited from healthy parents (23 CNV or 72%). Seven patients underwent sequencing. Not a single pathogenic nucleotide sequence variant was identified on the intact homologue, but in some cases, previously unreported variants of uncertain significance were found in genes not involved in CNV.

Проведено молекулярное кариотипирование 1176 больных с задержкой нервно-психического развития и выявлено 53 пациента с Х-сцепленными CNV. На основе результатов исследования разработан и апробирован алгоритм диагностики для пациентов, несущих Х-сцепленные CNV, который предполагает анализ патогенетической значимости CNV с использованием баз данных (DGV, OMIM и DECIPHER) и исследование статуса инактивации Х-хромосомы у носительниц CNV. Предложенный комплексный подход позволяет выявлять патогенетически значимые микроперестройки на хромосоме Х в семьях и проводить для этих семей персонализированное медико-генетическое консультирование. Molecular karyotyping of 1176 patients with neuropsychiatric development delay was performed and 53 patients with X-linked CNVs were identified. Based on the results, a diagnostic algorithm was developed and tested for patients carrying X-linked CNV. The algorithm involves the analysis of pathogenic significance of CNV using databases (DGV, OMIM and DECIPHER) and investigating the X-chromosome inactivation in CNV carriers. An integrated approach makes it possible to identify pathogenetically significant rearrangements on the X-chromosome in families and perform personalized genetic counseling for these families.

The study aimed to search for mutations in the ATP7B gene using massively parallel sequencing in patients with Wilson disease in the Tomsk region. For 42 patients with suspected Wilson's disease (aged from 1 to 33 years) was performed molecular genetic analysis. Enrichment of the interest genome regions was carried out by the long-range PCR. DNA libraries with ligated adapters were constructed with Nextera DNA Flex (Illumina, USA) kit. Sequencing was performed on the Illumina MiSeq platform (Illumina, USA). As a result of this work, we identified 9 pathogenic genetic variants. All variants were previously described in the literature and were found in patients with Wilson's disease. Five missense mutations, one splice site mutation, and 3 frameshift mutations were identified. In patients with Wilson's disease in the Tomsk region, the most common variant was c.3207C>A, this variant is the most common both in the Russian Federation and in other European populations. Also, a pathogenic variant c.3036dupC was found, which is probably endemic to the Russian Federation.

The review considers monogenic and chromosomal mutations associated with X-linked intellectual disability. Peculiarities of the development of the clinical phenotype in cases of different mutations were described. Special attention is paid to X-linked CNVs (microdeletions and microduplications). Chromosomal microaberrations most frequently found in patients with intellectual disability are presented. A modifying effect of X chromosome inactivation on the phenotype of carriers of X-linked mutations is discussed. The problems of interpretation of the clinical significance of X-linked CNVs are considered.

Abstract Study question To investigate the prevalence and effect of (mosaic) de novo genomic aberrations in recurrent pregnancy loss (RPL) and sporadic abortion (SA). Summary answer Prevalence of maternal uniparental disomies (UPDs) was high in both cohorts. While chromosomal UPDs were found in both cohorts, genome wide UPDs were RPL specific. What is known already Spontaneous abortion occurs in 10–15% of clinically recognized pregnancies and recurrent pregnancy loss in 1–3%. SA and RPL are associated with reduced quality of life. Multiple factors contribute to SA and RPL, such as uterine malformations and parental/fetal chromosomal abnormalities. However, in ∼60% of SA and RPL the cause remains unknown. UPD is defined as the presence of two homologues chromosomes originating from a single parent. This phenomenon can lead to imprinting disorders that are characterised by clinical features affecting growth, development and metabolism in liveborn offspring. However, it could also be responsible for pregnancy loss. Study design, size, duration We recruited 32 families with pregnancy loss (n = 16 RPL cohort, n = 16 SA cohort) with no known genetic predispositions and normal karyotyping results in both parents and the fetus. Average maternal age was 28.68 years (SD = 5.43), paternal age 30.3 years (SD = 5.53), and the gestational age at pregnancy loss was 8.65 weeks (SD = 2.47). The average number of miscarriages in the RPL group was 3.57 (SD = 0.84). We profiled the genomic landscape of both cohorts using SNP typing. Participants/materials, setting, methods We isolated DNA from blood of both parents and the placental tissues from the miscarried products of conception. The placenta tissues were sampled from two distinct extraembryonic and embryonic germ layers, the extraembryonic mesoderm and the chorionic villi cytotrophoblast. Subsequently, we performed SNP-genotyping using Illumina’s Global-Screening Array–24 v2.0 BeadChips and applied haplarithmisis to delineate allelic architecture of fetal tissues of both cohorts. This allowed us to detect large de novo copy-number and -neutral (>10kb) changes. Main results and the role of chance In this pilot study, we have analyzed 132 DNA samples (n = 32 families), of which 16 families were in the RPL cohort and 16 in the SA cohort. Within the RPL cohort, we found: one family with mosaic genome wide hexaploidy both in the extraembryonic mesoderm and chorionic villi, one family with a non-mosaic genome wide hetero UPD of the chorionic villi tissue, one family with a mosaic UPD of chromosome 14 in both tissues and tetraploidy exclusively in the chorionic villi, one family with a mosaic UPD of chromosome 16 in both tissues, one family with a mosaic UPD of chromosome 6 in both tissues, and another family with a mosaic UPD of chromosome 5 in the extraembryonic mesoderm. Within the SA group, one family showed a UPD of chromosome 7 and another family showed a segmental UPD of chromosome 5 in both tissues. Strikingly, all the UPDs found in this study were maternal in origin. Limitations, reasons for caution The main limitation of this study is the resolution of detecting copy-neutral and copy-number variations, which is an inherent limiting factor of SNP-array technology. In addition, in the sample in which we observed non-mosaic genome wide UPD, maternal contamination is likely that can be investigated by other technologies. Wider implications of the findings: Multiple genome wide UPDs are found in the RPL group but none in the SA group, indicating an association between genome wide mosaic UPD and RPL. These findings could lead to a better understanding of causative factors for SA and RPL and the need for a SNP-based non-invasive prenatal testing. Trial registration number Not applicable

Болезнь Вильсона-Коновалова - редкое аутосомно-рецессивное заболевание, которое характеризуется патологическим накоплением меди в печени, головном мозге и других тканях. Дифференциальная диагностика болезни Вильсона-Коновалова представляет собой сложную задачу вследствие выраженной гетерогенности клинических проявлений. Это подчеркивает важность разработки как новых методов диагностики, так и усовершенствования существующих. В рамках настоящего исследования было проведено сравнение клинической диагностики заболевания с результатами молекулярно-генетических исследований. Проанализировано 42 пациента с подозрением на болезнь Вильсона-Коновалова. Произведена оценка значения биохимических показателей метаболизма меди (концентрация церулоплазмина, щелочной фосфатазы, общего билирубина, АСТ, АЛТ сыворотки крови, содержание меди в печени, экскреция меди с мочой) согласно Лейпцигской количественной шкале. Для молекулярно-генетического анализа использовали геномную ДНК. Обогащение интересуемых регионов генома проводилось с помощью ПЦР длинных фрагментов. Для подготовки ДНК библиотек был использован набор Nextera DNA Flex (Illumina, США). Секвенирование проводилось на приборе Illumina MiSeq (Illumina, США). В результате исследования в 62,5% случаев у пациентов, направленных на подтверждение диагноза (по Лейпцигской количественной шкале), были найдены мутации в гене ATP7B, что подтверждает ценность комплексной диагностики по Лейпцигской количественной шкале с учетом клинической симптоматики и лабораторных показателей метаболизма меди. Wilson’s disease is a rare autosomal recessive disorder characterized by abnormal accumulation of copper in the liver, brain, and other tissues. Wilson’s disease differential diagnosis is a difficult task due to the pronounced clinical heterogeneity. This emphasizes the importance of developing both new diagnostic methods and improving existing ones. As part of this study, we compared clinical diagnostics with the results of molecular genetic studies. We analyzed 42 patients with suspected Wilson’s disease. The biochemical parameters copper metabolism values were assessed (serum ceruloplasmin concentration, liver copper content, urinary copper excretion, alkaline phosphatase, total bilirubin, AST, ALT) according to the Leipzig quantitative scale. We used genomic DNA for molecular genetic analysis. Regions of interest in the genome was enriched using long-range PCR. The Nextera DNA Flex kit (Illumina, USA) was used to prepare DNA libraries. Sequencing was performed on an Illumina MiSeq device (Illumina, USA). As a result of the study, in 62.5% of cases in patients aimed at confirming the diagnosis (according to the Leipzig quantitative scale), we found mutations in the ATP7B gene, which confirms the value of a comprehensive diagnosis according to the Leipzig quantitative scale, taking into account the clinical symptoms and copper metabolism laboratory parameters.