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Diagnostics (Basel, Switzerland) Jun 2024The diagnosis of hereditary skin tumors is difficult for "old" diagnostic tools such as immunohistochemistry. Whole-exome sequencing analysis as a "new" diagnostic tool...
The diagnosis of hereditary skin tumors is difficult for "old" diagnostic tools such as immunohistochemistry. Whole-exome sequencing analysis as a "new" diagnostic tool enables us to make a final diagnosis in spite of unknown hereditary diseases in the past. Hereditary leiomyomatosis and renal cell cancer are autosomal dominant hereditary cancer syndromes characterized by uterine myomas, cutaneous leiomyomas, and aggressive renal cell cancer. The syndrome is associated with pathogenic germline variants in the fumarate hydratase gene. Herein, we demonstrate a pathogenic germline variant of the fumarate hydratase gene in a 60-year-old woman with multiple cutaneous leiomyomas, leading to the diagnosis of hereditary leiomyomatosis and renal cell cancer. Whole-exome sequencing analysis using genomic DNA extracted from peripheral blood leukocytes revealed one germline variant in the FH gene on chromosome 1 (c.290G>A, p.Gly97Asp). She received total hysterectomy due to uterine myoma, which strongly supported the diagnosis. No tumor was detected in her kidney by computed tomography and ultrasound examination. Genetic examination for the mutation of the fumarate hydratase gene is important in order to reach the correct diagnosis and to detect renal cancer at its early stage.
PubMed: 38928693
DOI: 10.3390/diagnostics14121279 -
International Journal of Molecular... Jun 2024A homozygous mutation of the gene causes autosomal recessive familial type 19 of Parkinson's disease (PARK19). To test the hypothesis that PARK19 DNAJC6 mutations...
A homozygous mutation of the gene causes autosomal recessive familial type 19 of Parkinson's disease (PARK19). To test the hypothesis that PARK19 DNAJC6 mutations induce the neurodegeneration of dopaminergic cells by reducing the protein expression of functional DNAJC6 and causing DNAJC6 paucity, an in vitro PARK19 model was constructed by using shRNA-mediated gene silencing of endogenous DANJC6 in differentiated human SH-SY5Y dopaminergic neurons. shRNA targeting DNAJC6 induced the neurodegeneration of dopaminergic cells. DNAJC6 paucity reduced the level of cytosolic clathrin heavy chain and the number of lysosomes in dopaminergic neurons. A DNAJC6 paucity-induced reduction in the lysosomal number downregulated the protein level of lysosomal protease cathepsin D and impaired macroautophagy, resulting in the upregulation of pathologic α-synuclein or phospho-α-synuclein in the endoplasmic reticulum (ER) and mitochondria. The expression of α-synuclein shRNA or cathepsin D blocked the DNAJC6 deficiency-evoked degeneration of dopaminergic cells. An increase in ER α-synuclein or phospho-α-synuclein caused by DNAJC6 paucity activated ER stress, the unfolded protein response and ER stress-triggered apoptotic signaling. The lack of DNAJC6-induced upregulation of mitochondrial α-synuclein depolarized the mitochondrial membrane potential and elevated the mitochondrial level of superoxide. The DNAJC6 paucity-evoked ER stress-related apoptotic cascade, mitochondrial malfunction and oxidative stress induced the degeneration of dopaminergic neurons via activating mitochondrial pro-apoptotic signaling. In contrast with the neuroprotective function of WT DNAJC6, the PARK19 DNAJC6 mutants (Q789X or R927G) failed to attenuate the tunicamycin- or rotenone-induced upregulation of pathologic α-synuclein and stimulation of apoptotic signaling. Our data suggest that PARK19 mutation-induced DNAJC6 paucity causes the degeneration of dopaminergic neurons via downregulating protease cathepsin D and upregulating neurotoxic α-synuclein. Our results also indicate that PARK19 mutation (Q789X or R927G) impairs the DNAJC6-mediated neuroprotective function.
Topics: Cathepsin D; Dopaminergic Neurons; Humans; alpha-Synuclein; HSP40 Heat-Shock Proteins; Endoplasmic Reticulum Stress; Up-Regulation; Parkinson Disease; Mitochondria; Lysosomes; Down-Regulation; Apoptosis; Cell Line, Tumor
PubMed: 38928416
DOI: 10.3390/ijms25126711 -
International Journal of Molecular... Jun 2024Cystic fibrosis (CF), also known as mucoviscidosis, is the most common autosomal recessive genetic disease in the Caucasian population, with an estimated frequency of... (Review)
Review
Cystic fibrosis (CF), also known as mucoviscidosis, is the most common autosomal recessive genetic disease in the Caucasian population, with an estimated frequency of 1:2000-3000 live births. CF results from the mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene localized in the long arm of chromosome 7. The product of CFTR gene expression is CFTR protein, an adenosine triphosphate (ATP)-binding cassette (ABC) transporter that regulates the transport of chloride ions (Cl) across the apical cell membrane. Primary manifestations of CF include chronic lung and pancreas function impairment secondary to the production of thick, sticky mucus resulting from dehydrated secretions. It is well known that CF can cause both anterior and posterior ocular abnormalities. Conjunctival and corneal xerosis and dry eye disease symptoms are the most characteristic manifestations in the anterior segment. In contrast, the most typical anatomical and functional changes relating to the posterior segment of the eye include defects in the retinal nerve fiber layer (RNFL), vascular abnormalities, and visual disturbances, such as reduced contrast sensitivity and abnormal dark adaptation. However, the complete background of ophthalmic manifestations in the course of CF has yet to be discovered. This review summarizes the current knowledge regarding ocular changes in cystic fibrosis.
Topics: Humans; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Eye Diseases; Mutation; Animals
PubMed: 38928397
DOI: 10.3390/ijms25126692 -
International Journal of Molecular... Jun 2024We present a case involving a patient whose clinical phenotype aligns with oculocutaneous albinism (OCA), yet exhibits a complex genotype primarily characterized by...
We present a case involving a patient whose clinical phenotype aligns with oculocutaneous albinism (OCA), yet exhibits a complex genotype primarily characterized by variants of unknown significance (VUS). An 11-year-old boy manifested iris hypopigmentation and translucency, pronounced photophobia, diminished visual acuity and stereopsis, nystagmus, reduced pigmentation of the retina, and foveal hypoplasia. Genetic testing was performed. A heterozygous missense VUS c.230A>G, p.(Gln77Arg), a heterozygous missense VUS c.1307G>C, p.(Gly436Ala), and a heterozygous missense variant c.1205G>A, p.(Arg402Gln) which was classified as a risk factor, were identified. We hypothesized that the c.1307G>C, p.(Gly436Ala) variant is in genetic disequilibrium with the c.1205G>A, p.(Arg402Gln) variant leading to deficient expression of melanogenic enzymes in retinal cells, resulting in the manifestation of mild OCA. Additionally, this study represents the case where we did not detect chiasmal misrouting in visual evoked potentials, nor did we observe a shift in the distribution of ganglion cell thickness from a temporal to a central position. Moreover, our patient's case supports the probable benign nature of the c.230A>G, p.(Gln77Arg) variant.
Topics: Humans; Male; Child; Calpain; Monophenol Monooxygenase; Mutation, Missense; Vitreoretinopathy, Proliferative; Albinism, Oculocutaneous; Phenotype; Pedigree
PubMed: 38928147
DOI: 10.3390/ijms25126442 -
International Journal of Molecular... Jun 2024Mutations in the gene are associated with autosomal recessive spastic ataxia of Charlevoix-Saguenay disease (ARSACS) or complex clinical phenotypes of...
Mutations in the gene are associated with autosomal recessive spastic ataxia of Charlevoix-Saguenay disease (ARSACS) or complex clinical phenotypes of Charcot-Marie-Tooth disease (CMT). This study aimed to identify mutations in a Korean CMT cohort with cerebellar ataxia and spasticity by whole exome sequencing (WES). As a result, eight pathogenic mutations in four families were identified as the underlying causes of these complex phenotypes. The prevalence of CMT families with mutations was determined to be 0.3%. All the patients showed sensory, motor, and gait disturbances with increased deep tendon reflexes. Lower limb magnetic resonance imaging (MRI) was performed in four patients and all had fatty replacements. Of note, they all had similar fatty infiltrations between the proximal and distal lower limb muscles, different from the neuromuscular imaging feature in most CMT patients without mutations who had distal dominant fatty involvement. Therefore, these findings were considered a characteristic feature in CMT patients with mutations. Although further studies with more cases are needed, our results highlight lower extremity MRI findings in CMT patients with mutations and broaden the clinical spectrum. We suggest screening for in recessive CMT patients with complex phenotypes of ataxia and spasticity.
Topics: Humans; Male; Charcot-Marie-Tooth Disease; Female; Mutation; Adult; Republic of Korea; Muscle Spasticity; Heterozygote; Cohort Studies; Middle Aged; Magnetic Resonance Imaging; Heat-Shock Proteins; Pedigree; Exome Sequencing; Cerebellar Ataxia; Phenotype; Adolescent; Young Adult
PubMed: 38928084
DOI: 10.3390/ijms25126378 -
Genes Jun 2024Retinitis pigmentosa (RP) is a heterogeneous inherited retinal disorder. Mutations in cause autosomal recessive (AR) RP. We aimed to characterize the genotype,...
Retinitis pigmentosa (RP) is a heterogeneous inherited retinal disorder. Mutations in cause autosomal recessive (AR) RP. We aimed to characterize the genotype, expression pattern, and phenotype in a large cohort of cases. Sanger and whole exome sequencing were used to identify the variants. Medical records were reviewed and analyzed. Thirty-one patients with biallelic mutations were identified: 28 homozygous for c.226C>T (p.R76*), 2 compound heterozygous for p.R76* and c.3G>A (p.M1?), and one homozygous for c.247C>T (p.R83*). c.226C>T is a founder mutation among patients of Jewish descent. The clinical parameters were less severe in compared to and cases. RT-PCR analysis in fibroblast cells revealed the presence of four different transcripts in both WT and mutant samples with a lower percentage of the WT transcript in patients. Sequence analysis identified an exonic sequence enhancer (ESE) that includes the c.226 position which is affected by the mutation. mutations are an uncommon cause of IRD worldwide but are not rare among Ashkenazi Jews. Our data indicate that p.R76* affect an ESE which in turn results in the pronounced skipping of exon 3. Therefore, RNA-based therapies might show low efficacy since the mutant transcripts are spliced.
Topics: Humans; Retinitis Pigmentosa; Female; Male; Mutation; Adult; Jews; Exome Sequencing; Pedigree; Eye Proteins; Phenotype; Middle Aged; Adolescent
PubMed: 38927740
DOI: 10.3390/genes15060804 -
Genes Jun 2024Mutations in the gene (S phase Cyclin A-Associated Protein residing in the Endoplasmic Reticulum) have recently been associated with retinitis pigmentosa (RP) and...
Mutations in the gene (S phase Cyclin A-Associated Protein residing in the Endoplasmic Reticulum) have recently been associated with retinitis pigmentosa (RP) and intellectual disability (ID). In 2011, a possible involvement of in human diseases was discovered for the first time due to the identification of a homozygous mutation causing ID in an Iranian family. Later, five studies were published in 2019 that described patients with autosomal recessive syndromic retinitis pigmentosa (arRP) accompanied by ID and attention-deficit/hyperactivity disorder (ADHD). This present study describes three patients from an Arab consanguineous family in Israel with similar clinical features of the SCAPER syndrome. In addition, new manifestations of ocular symptoms, nystagmus, glaucoma, and elevator palsy, were observed. Genetic testing of the patients and both parents via whole-exome sequencing revealed the homozygous mutation c.2023-2A>G in . Phenotypic and genotypic descriptions for all available cases described in the literature including our current three cases (37 cases) were carried out, in addition to a bioinformatics analysis for all the genetic variants that was undertaken. Our study confirms and extends the clinical manifestations of SCAPER-related disorders.
Topics: Adolescent; Adult; Female; Humans; Carrier Proteins; Computational Biology; Consanguinity; Exome Sequencing; Genes, Recessive; Homozygote; Intellectual Disability; Intercellular Signaling Peptides and Proteins; Mutation; Pedigree; Phenotype; Retinitis Pigmentosa
PubMed: 38927727
DOI: 10.3390/genes15060791 -
Genes Jun 2024Mosaicism for autosomal trisomy is uncommon in clinical practice. However, despite its rarity among both prenatally and postnatally diagnoses, there are a large number...
Mosaicism for autosomal trisomy is uncommon in clinical practice. However, despite its rarity among both prenatally and postnatally diagnoses, there are a large number of characterized and published cases. Surprisingly, in contrast to regular trisomies, no attempts at systematic analyses of mosaic carriers' demographics were undertaken. This is the first study aimed to address this gap. For that, we have screened more than eight hundred publications on mosaic trisomies, reviewing data including gender and clinical status of mosaic carriers, maternal age and reproductive history. In total, 596 publications were eligible for analysis, containing data on 948 prenatal diagnoses, including true fetal mosaicism (TFM) and confined placental mosaicism (CPM), and on 318 cases of postnatally detected mosaicism (PNM). No difference was found in maternal age between normal pregnancy outcomes with appropriate birth weight and those with intrauterine growth restriction. Unexpectedly, a higher proportion of advanced maternal ages (AMA) was found in normal outcomes compared to abnormal ones (abnormal fetus or newborn) and fetal losses, 73% vs. 56% and 50%, = 0.0015 and 0.0011, correspondingly. Another intriguing finding was a higher AMA proportion in mosaic carriers with concomitant uniparental disomy (UPD) for chromosomes 7, 14, 15, and 16 compared to carriers with biparental disomy (BPD) (72% vs. 58%, 92% vs. 55%, 87% vs. 78%, and 65% vs. 24%, correspondingly); overall figures were 78% vs. 48%, 0.0026. Analysis of reproductive histories showed a very poor reporting but almost two-fold higher rate of mothers reporting a previous fetal loss from PNM cohort (in which almost all patients were clinically abnormal) compared to mothers from the TFM and CPM cohorts (with a large proportion of normal outcomes), 30% vs. 16%, = 0.0072. The occurrence of a previous pregnancy with a chromosome abnormality was 1 in 13 in the prenatal cohort and 1 in 16 in the postnatal cohort, which are five-fold higher compared to published studies on non-mosaic trisomies. We consider the data obtained in this study to be preliminary despite the magnitude of the literature reviewed since reporting of detailed data was mostly poor, and therefore, the studied cohorts do not represent "big data". Nevertheless, the information obtained is useful both for clinical genetic counseling and for modeling further studies.
Topics: Humans; Mosaicism; Maternal Age; Female; Pregnancy; Trisomy; Reproductive History; Adult; Prenatal Diagnosis; Uniparental Disomy; Male
PubMed: 38927714
DOI: 10.3390/genes15060778 -
Genes Jun 2024The genetic bases of Alzheimer's disease (AD) and frontotemporal dementia (FTD) have been comprehensively studied, which is not the case for atypical cases not...
Rare Pathogenic Variants in Pooled Whole-Exome Sequencing Data Suggest Hyperammonemia as a Possible Cause of Dementia Not Classified as Alzheimer's Disease or Frontotemporal Dementia.
The genetic bases of Alzheimer's disease (AD) and frontotemporal dementia (FTD) have been comprehensively studied, which is not the case for atypical cases not classified into these diagnoses. In the present study, we aim to contribute to the molecular understanding of the development of non-AD and non-FTD dementia due to hyperammonemia caused by mutations in urea cycle genes. The analysis was performed by pooled whole-exome sequencing (WES) of 90 patients and by searching for rare pathogenic variants in autosomal genes for enzymes or transporters of the urea cycle pathway. The survey returned two rare pathogenic coding mutations leading to citrullinemia type I: rs148918985, p.Arg265Cys, C>T; and rs121908641, p.Gly390Arg, G>A in the argininosuccinate synthase 1 () gene. The p.Arg265Cys variant leads to enzyme deficiency, whereas p.Gly390Arg renders the enzyme inactive. These variants found in simple or compound heterozygosity can lead to the late-onset form of citrullinemia type I, associated with high ammonia levels, which can lead to cerebral dysfunction and thus to the development of dementia. The presence of urea cycle disorder-causing mutations can be used for the early initiation of antihyperammonemia therapy in order to prevent the neurotoxic effects.
Topics: Humans; Exome Sequencing; Hyperammonemia; Frontotemporal Dementia; Alzheimer Disease; Female; Male; Argininosuccinate Synthase; Aged; Mutation; Middle Aged; Citrullinemia; Dementia
PubMed: 38927689
DOI: 10.3390/genes15060753 -
Genes May 2024Hereditary sensory and autonomic neuropathy type 1 is an autosomal dominant neuropathy caused by the or variants. These variants modify the preferred substrate of...
Hereditary sensory and autonomic neuropathy type 1 is an autosomal dominant neuropathy caused by the or variants. These variants modify the preferred substrate of serine palmitoyl transferase, responsible for the first step of sphingolipids synthesis, leading to accumulation of cytotoxic deoxysphingolipids. Diagnosis of HSAN1 is based on clinical symptoms, mainly progressive loss of distal sensory keep, and genetic analysis. Identifying new or "" variants raises the question as to their pathogenicity. This work focused on characterizing six new variants using in silico prediction tools, new meta-scores, 3D modeling, and functional testing to establish their pathogenicity. Variants from six patients with HSAN1 were studied. , CADD and REVEL scores and the 3D modeling software MITZLI were used to characterize the pathogenic effect of the variants. Functional tests based on plasma sphingolipids quantification (total deoxysphinganine, ceramides, and dihydroceramides) were performed by tandem mass spectrometry. In silico predictors did not provide very contrasting results when functional tests discriminated the different variants according to their impact on deoxysphinganine level or canonical sphingolipids synthesis. Two variants were newly described as pathogenic: NM_006415.4:c.998A>G and NM_006415.4:c.1015G>A. The combination of the different tools provides arguments to establish the pathogenicity of these new variants. When available, functional testing remains the best option to establish the in vivo impact of a variant. Moreover, the comprehension of metabolic dysregulation offers opportunities to develop new therapeutic strategies for these genetic disorders.
Topics: Humans; Serine C-Palmitoyltransferase; Hereditary Sensory and Autonomic Neuropathies; Mutation, Missense; Male; Female; Sphingolipids; Adult; Middle Aged
PubMed: 38927628
DOI: 10.3390/genes15060692