Limb-girdle muscular dystrophies (LGMD) constitute a heterogeneous group of genetic disorders characterized by progressive muscle weakness and atrophy, predominantly affecting the muscles of the pelvic and shoulder girdles. LGMD R27, linked to biallelic pathogenic variants in the gene, was recently described, and to date, only 27 cases has been published in three reports. Here, we present two siblings exhibiting a severe clinical phenotype of LGMD R27, associated with a novel homozygous frameshift variant [c.
View Article and Find Full Text PDFBackground: The gene encodes ATP-dependent RNA helicase SUPV3L1, which is a part of the mitochondrial degradosome complex or SUV3. SUPV3L1 unwinds secondary structures of mitochondrial RNA (mtRNA) and facilitates the degradation of mtRNA molecules. A nonsense homozygous variant in the gene was recently associated with mitochondrial disease.
View Article and Find Full Text PDFA genetic diagnosis of primary cardiomyopathies can be a long-unmet need in patients with complex phenotypes. We investigated a three-generation family with cardiomyopathy and various extracardiac abnormalities that had long sought a precise diagnosis. The 41-year-old proband had hypertrophic cardiomyopathy (HCM), left ventricular noncompaction, myocardial fibrosis, arrhythmias, and a short stature.
View Article and Find Full Text PDFPathogenic variants in the gene lead to a spectrum of rare autosomal recessive phenotypes, including osteogenesis imperfecta (OI) Type XI, Bruck syndrome Type I (BS I), and the congenital arthrogryposis-like phenotype (AG), each with variable clinical manifestations that are crucial for diagnosis. This study analyzed the clinical-genetic characteristics of patients with these conditions, focusing on both known and newly identified variants. We examined data from 15 patients, presenting symptoms of OI and joint contractures.
View Article and Find Full Text PDFCongenital myasthenic syndrome with episodic apnea is associated with pathogenic variants in the gene. While respiratory disorders and oculomotor findings are commonly reported in affected individuals, a subset of patients only present with muscle weakness and/or ptosis but not apneic crises. In this case series, we describe five individuals with exercise intolerance caused by single nucleotide variants in the gene.
View Article and Find Full Text PDFThe gene encodes a homeobox transcription factor pivotal in the development of rhombomere 4. Biallelic pathogenic variants in this gene are associated with congenital facial paresis type 3 (HCFP3). Only seven single nucleotide variants have been reported in the literature to date.
View Article and Find Full Text PDFBackground: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited disease with unknown mechanisms and a broad phenotypic spectrum. It is caused by pathogenic variants in the gene. The symptoms of the disease mainly include recurrent strokes with vascular risk factors, migraine with aura, dementia, and mood disturbances.
View Article and Find Full Text PDFHere we present a patient with a cranioectodermal phenotype associated with pathogenic variants in the gene. Most frequently, pathogenic variants in correspond to the phenotype of Mainzer-Saldino syndrome. Only four patients have previously been described with this cranioectodermal phenotype and variants in .
View Article and Find Full Text PDFObjective: Variants in GABRA1 have been associated with a broad epilepsy spectrum, ranging from genetic generalized epilepsies to developmental and epileptic encephalopathies. However, our understanding of what determines the phenotype severity and best treatment options remains inadequate. We therefore aimed to analyze the electroclinical features and the functional effects of GABRA1 variants to establish genotype-phenotype correlations.
View Article and Find Full Text PDFThe implementation of NGS methods into clinical practice allowed researchers effectively to establish the molecular cause of a disorder in cases of a genetically heterogeneous pathology. In cases of several potentially causative variants, we need additional analysis that can help in choosing a proper causative variant. In the current study, we described a family case of hereditary motor and sensory neuropathy (HMSN) type 1 (Charcot-Marie-Tooth disease).
View Article and Find Full Text PDFWe present a patient with unusual episodes of muscular weakness due to homozygous deletion of exon 2 in the gene. Forty-three patients from 33 families were previously described with homozygous and compound heterozygous, predominantly loss of function (LoF) variants in the gene that lead to autosomal recessive myopathy with extrapyramidal signs. Most described patients developed muscle weakness and elevated CK levels, and half of the patients had progressive extrapyramidal signs and learning disabilities.
View Article and Find Full Text PDFGNE myopathy (GNEM) is a rare hereditary disease, but at the same time, it is the most common distal myopathy in several countries due to a founder effect of some pathogenic variants in the gene. We collected the largest cohort of patients with GNEM from Russia and analyzed their mutational spectrum and clinical data. In our cohort, 10 novel variants were found, including 2 frameshift variants and 2 large deletions.
View Article and Find Full Text PDFMultiple epiphyseal dysplasias (MED) are a clinically and genetically heterogeneous group of skeletal dysplasias with a predominant lesion in the epiphyses of tubular bones. Variants in the SLC26A2 gene cause their autosomal recessive form (rMED or MED type 4). The accumulation of data regarding the genotype−phenotype correlation can help in the diagnosis and proper management of these patients.
View Article and Find Full Text PDFIntellectual development disorder (IDD) is characterized by a general deficit in intellectual and adaptive functioning. In recent years, there has been a growing interest in studying the genetic structure of IDD. Of particular difficulty are patients with non-specific IDD, for whom it is impossible to establish a clinical diagnosis without complex genetic diagnostics.
View Article and Find Full Text PDFInverted duplication syndrome with an adjacent terminal deletion of the short arm of chromosome 8-inv dup del(8p)-is a rare complex structural chromosomal rearrangement with a wide range of clinical manifestations. Molecular cytogenetic variants of chromosomal imbalance depend on the mechanism of rearrangement formation. We analyzed the clinical-genetic and molecular cytogenetic characteristics of the 8p inverted duplication/deletion syndrome, as well as the genotype-phenotype correlation in eight unrelated cases with the rearrangement of inv dup del(8p).
View Article and Find Full Text PDFBackground: Pycnodysostosis (PD, OMIM # 265800) is a rare variant of skeletal dysplasia with an autosomal recessive type of inheritance, characterized by a combination of specific features such as disproportionate nanism, generalized osteosclerosis, and distinct craniofacial dysmorphism. Radiographic features include acro-osteolysis of the distal phalanges in association with sclerosing bone lesions with multiple fractures. The polymorphism of the clinical manifestations of pycnodysostosis and low prevalence of the disorder lead to the difficulties with early.
View Article and Find Full Text PDFCongenital myopathy associated with pathogenic variants in the gene has long been considered native American myopathy (NAM). In 2017, the first case of a non-Amerindian patient with this myopathy was described. Here, we report the first Russian patient with NAM.
View Article and Find Full Text PDFThe significant variability in the clinical manifestations of COL2A1-associated skeletal dysplasias makes it necessary to conduct a clinical and genetic analysis of individual nosological variants, which will contribute to improving our understanding of the pathogenetic mechanisms and prognosis. We presented the clinical and genetic characteristics of 60 Russian pediatric patients with type II collagenopathies caused by previously described and newly identified variants in the gene. Diagnosis confirmation was carried out by new generation sequencing of the target panel with subsequent validation of the identified variants using automated Sanger sequencing.
View Article and Find Full Text PDFFour cases of autosomal dominant CNS disorders related to mutations and detected by massive parallel sequencing are reported: a non-familial case of episodic ataxia type 2 (EA2) with the previously reported mutation c.269_270insA (p.Tyr90Ter) in a 35-year-old man; familial hemiplegic migraine type 1 (FHM1) in a girl aged 3 years 10 months and her mother aged 38 yrs with a novel mutation 1829C>T (p.
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