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Iranian Journal of Public Health Feb 2024Holoprosencephaly, a complicated brain abnormality arising from incomplete prosencephalon cleavage, affects both the forebrain and the face. Holoprosencephaly Type 11,...
Holoprosencephaly, a complicated brain abnormality arising from incomplete prosencephalon cleavage, affects both the forebrain and the face. Holoprosencephaly Type 11, with variable expression or partial penetrance, is caused by pathogenic variants associated with the disrupted Sonic Hedgehog ()-pathway. Herein, we aimed to describe a family with genetic nose problems. After counselling and drawing pedigree in Farhud's Genetic Clinic, Tehran, Iran in 2021, DNA extraction of a proband and a few members of his family (patient and control) was conducted. Whole exome sequencing was utilized for detecting the gene and its variant in the proband with a nose deformity. The results were confirmed with Sanger sequencing. This variant was checked in other members by Sanger sequencing. Analysis of the Exome data showed a heterozygous splicing variant in the gene (NM_016952; c.3276+1G>T) in the proband who had a nose deformity and then the results were confirmed with Sanger sequencing. Such a variant was observed in Proband's brother with a nose deformity and was not observed in Proband's cousin with no abnormal phenotype. Recent investigations, in an Iranian family, with a heterozygous splicing mutation as a human candidate gene are discussed for the first time in relation to the likely pathogenesis of facial deformities, particularly nose deformity, in Holoprosencephaly.
PubMed: 38894838
DOI: 10.18502/ijph.v53i2.14933 -
International Journal of Molecular... Jun 2024Leber congenital amaurosis (LCA)/early-onset severe retinal dystrophy (EOSRD) stand as primary causes of incurable childhood blindness. This study investigates the...
Leber congenital amaurosis (LCA)/early-onset severe retinal dystrophy (EOSRD) stand as primary causes of incurable childhood blindness. This study investigates the clinical and molecular architecture of syndromic and non-syndromic LCA/EOSRD within a Chilean cohort (67 patients/60 families). Leveraging panel sequencing, 95.5% detection was achieved, revealing 17 genes and 126 variants (32 unique). , , and dominated (71.9%), with being the most prevalent (43.8%). Notably, four unique variants ( p.Glu415*, p.Ser1049Aspfs*40 and p.Cys948Tyr, p.Leu99Ile) constituted 62.7% of all disease alleles, indicating their importance for targeted analysis in Chilean patients. This study underscores a high degree of inbreeding in Chilean families affected by pediatric retinal blindness, resulting in a limited mutation repertoire. Furthermore, it complements and reinforces earlier reports, indicating the involvement of and as uncommon causes of LCA/EOSRD. These data hold significant value for patient and family counseling, pharmaceutical industry endeavors in personalized medicine, and future enrolment in gene therapy-based treatments, particularly with ongoing trials () or advancing preclinical developments ( and ).
Topics: Humans; Retinal Dystrophies; Chile; Male; Female; Child; Mutation; Child, Preschool; Alcohol Oxidoreductases; Membrane Proteins; Eye Proteins; Leber Congenital Amaurosis; Pedigree; Nerve Tissue Proteins; Adolescent; Alleles; Genetic Variation; Eye Diseases, Hereditary
PubMed: 38892339
DOI: 10.3390/ijms25116151 -
International Journal of Molecular... Jun 2024mutations cause X-linked amelogenesis imperfecta (AI), known as AI types IE, IIB, and IIC in Witkop's classification, characterized by hypoplastic (reduced thickness)...
mutations cause X-linked amelogenesis imperfecta (AI), known as AI types IE, IIB, and IIC in Witkop's classification, characterized by hypoplastic (reduced thickness) and/or hypomaturation (reduced hardness) enamel defects. In this study, we conducted whole exome analyses to unravel the disease-causing mutations for six AI families. Splicing assays, immunoblotting, and quantitative RT-PCR were conducted to investigate the molecular and cellular effects of the mutations. Four pathogenic variants (NM_182680.1:c.2T>C; c.29T>C; c.77del; c.145-1G>A) and a whole gene deletion (NG_012494.2:g.307534_403773del) were identified. The affected individuals exhibited enamel malformations, ranging from thin, poorly mineralized enamel with a "snow-capped" appearance to severe hypoplastic defects with minimal enamel. The c.145-1G>A mutation caused a -1 frameshift (NP_001133.1:p.Val35Cysfs*5). Overexpression of c.2T>C and c.29T>C demonstrated that mutant amelogenin proteins failed to be secreted, causing elevated endoplasmic reticulum stress and potential cell apoptosis. This study reveals a genotype-phenotype relationship for -associated AI: While amorphic mutations, including large deletions and 5' truncations, of cause hypoplastic-hypomaturation enamel with snow-capped teeth (AI types IIB and IIC) due to a complete loss of gene function, neomorphic variants, including signal peptide defects and 3' truncations, lead to severe hypoplastic/aplastic enamel (AI type IE) probably caused by "toxic" cellular effects of the mutant proteins.
Topics: Amelogenesis Imperfecta; Humans; Amelogenin; Male; Female; Genetic Association Studies; Mutation; Pedigree; Phenotype; Child; Endoplasmic Reticulum Stress; Genotype; Exome Sequencing
PubMed: 38892321
DOI: 10.3390/ijms25116132 -
International Journal of Molecular... May 2024is the most frequently mutated gene leading to inherited retinal disease (IRD) with over 2200 pathogenic variants reported to date. Of these, ~1% are copy number...
is the most frequently mutated gene leading to inherited retinal disease (IRD) with over 2200 pathogenic variants reported to date. Of these, ~1% are copy number variants (CNVs) involving the deletion or duplication of genomic regions, typically >50 nucleotides in length. An in-depth assessment of the current literature based on the public database LOVD, regarding the presence of known CNVs and structural variants in , and additional sequencing analysis of using single-molecule Molecular Inversion Probes (smMIPs) for 148 probands highlighted recurrent and novel CNVs associated with -associated retinopathies. An analysis of the coverage depth in the sequencing data led to the identification of eleven deletions (six novel and five recurrent), three duplications (one novel and two recurrent) and one complex CNV. Of particular interest was the identification of a complex defect, i.e., a 15.3 kb duplicated segment encompassing exon 31 through intron 41 that was inserted at the junction of a downstream 2.7 kb deletion encompassing intron 44 through intron 47. In addition, we identified a 7.0 kb tandem duplication of intron 1 in three cases. The identification of CNVs in can provide patients and their families with a genetic diagnosis whilst expanding our understanding of the complexity of diseases caused by variants.
Topics: Humans; DNA Copy Number Variations; ATP-Binding Cassette Transporters; Retinal Diseases; Female; Male; Pedigree; Introns; Exons; Gene Duplication
PubMed: 38892127
DOI: 10.3390/ijms25115940 -
International Journal of Molecular... May 2024Pathogenic variants in the gene lead to a systemic disease with karyomegalic interstitial nephritis (KIN) at the forefront clinically. The phenotypic-genotypic features...
Pathogenic variants in the gene lead to a systemic disease with karyomegalic interstitial nephritis (KIN) at the forefront clinically. The phenotypic-genotypic features of a mutation-related disease involving five members of a Hungarian Caucasian family are presented. Each had adult-onset chronic kidney disease of unknown cause treated with renal replacement therapy and elevated liver enzymes. Short stature, emaciation, latte-colored skin, freckles, and a hawk-like nose in four patients, a limited intellect in two patients, and chronic restrictive lung disease in one patient completed the phenotype. Severe infections occurred in four patients. All five patients had ceased. Four patients underwent autopsy. KIN and extrarenal karyomegaly were observed histologically; the livers showed no specific abnormality. The genotyping using formalin-fixed tissue samples detected a hitherto undescribed homozygous mutation (c.1673_1674insT/p.Met558lfs*4; exon 5) in three of these patients and a heterozygous mutation in one patient. The reason for the heterozygosity is discussed. In addition, 56 family members consented to the screening for mutation from which 17 individuals proved to be heterozygous carriers; a blood chemistry evaluation of their kidney and liver function did not find any abnormality. The clinical presentation of FAN1-related disease was multifaceted, and not yet described manifestations were observed besides kidney and liver disease. Mutation in this gene should be suspected in adults with small kidneys of unknown cause, elevated liver enzymes, and recurrent infections, even without a family history.
Topics: Humans; Male; Female; Hungary; Mutation; Adult; Phenotype; Pedigree; Middle Aged; Exodeoxyribonucleases; Multifunctional Enzymes; Endodeoxyribonucleases; Genotype; Renal Insufficiency, Chronic
PubMed: 38892095
DOI: 10.3390/ijms25115907 -
International Journal of Molecular... May 2024Pathogenic variants in have been associated with a wide spectrum of muscular conditions: the laminopathies. -related congenital muscular dystrophy is a laminopathy...
Pathogenic variants in have been associated with a wide spectrum of muscular conditions: the laminopathies. -related congenital muscular dystrophy is a laminopathy characterised by the early onset of symptoms and often leads to a fatal outcome at young ages. Children face a heightened risk of malignant arrhythmias. No established paediatric protocols for managing this condition are available. We review published cases and provide insights into disease progression in two twin sisters with -related muscular dystrophy. Our objective is to propose a cardiac surveillance and management plan tailored specifically for paediatric patients. We present a family of five members, including two twin sisters with -related muscular dystrophy. A comprehensive neuromuscular and cardiac work-up was performed in all family members. Genetic analysis using massive sequencing technology was performed in both twins. Clinical assessment showed that only the twins showed diagnoses of -related muscular dystrophy. Follow-up showed an early onset of symptoms and life-threatening arrhythmias, with differing disease progressions despite both twins passing away. Genetic analysis identified a de novo rare missense deleterious variant in the gene. Other additional rare variants were identified in genes associated with myasthenic syndrome. Early-onset neuromuscular symptoms could be related to a prognosis of worse life-threatening arrhythmias in related muscular dystrophy. Being a carrier of other rare variants may be a modifying factor in the progression of the phenotype, although further studies are needed. There is a pressing need for specific cardiac recommendations tailored to the paediatric population to mitigate the risk of malignant arrhythmias.
Topics: Humans; Lamin Type A; Twins, Monozygotic; Female; Muscular Dystrophies; Male; Child; Pedigree; Child, Preschool; Arrhythmias, Cardiac
PubMed: 38892025
DOI: 10.3390/ijms25115836 -
International Journal of Molecular... May 2024Retinitis pigmentosa (RP) is an inherited retinal dystrophy caused by the loss of photoreceptors and retinal pigment epithelial atrophy, leading to severe visual...
Retinitis pigmentosa (RP) is an inherited retinal dystrophy caused by the loss of photoreceptors and retinal pigment epithelial atrophy, leading to severe visual impairment or blindness. RP can be classified as nonsyndromic or syndromic with complex clinical phenotypes. Three unrelated Polish probands affected with retinitis pigmentosa coexisting with cerebellar ataxia were recruited for this study. Clinical heterogeneity and delayed appearance of typical disease symptoms significantly prolonged the patients' diagnostic process. Therefore, many clinical and genetic tests have been performed in the past. Here, we provide detailed clinical and genetic analysis results of the patients. Whole-exome sequencing (WES) and targeted NGS analysis allow the identification of four novel and two previously reported variants in the following genes: , , and The use of next-generation sequencing (NGS) methods finally allowed for confirmation of the clinical diagnosis. Ultra-rare diseases such as PHARC, PCARP, and Oliver-McFarlane syndromes were diagnosed in patients, respectively. Our findings confirmed the importance of the application of next-generation sequencing methods, especially in ultra-rare genetic disorders with overlapping features.
Topics: Humans; Retinitis Pigmentosa; Male; Female; Exome Sequencing; Pedigree; High-Throughput Nucleotide Sequencing; Adult; Cerebellar Ataxia; Membrane Transport Proteins; Monoacylglycerol Lipases; Mutation; Ataxia; Phenotype; Acyltransferases; Cataract; Phospholipases; Polyneuropathies
PubMed: 38891946
DOI: 10.3390/ijms25115759 -
International Journal of Molecular... May 2024Gilles de la Tourette syndrome (GTS) is a neurodevelopmental psychiatric disorder with complex and elusive etiology with a significant role of genetic factors. The aim...
Gilles de la Tourette syndrome (GTS) is a neurodevelopmental psychiatric disorder with complex and elusive etiology with a significant role of genetic factors. The aim of this study was to identify structural variants that could be associated with familial GTS. The study group comprised 17 multiplex families with 80 patients. Structural variants were identified from whole-genome sequencing data and followed by co-segregation and bioinformatic analyses. The localization of these variants was used to select candidate genes and create gene sets, which were subsequently processed in gene ontology and pathway enrichment analysis. Seventy putative pathogenic variants shared among affected individuals within one family but not present in the control group were identified. Only four private or rare deletions were exonic in , , , and genes. Notably, the gene is involved in cochlear development and sensory perception of sound, a process that was associated previously with familial GTS. In addition, two rare variants and three not present in the control group were co-segregating with the disease in two families, and uncommon insertions in and were co-segregating in three families each. Enrichment analysis showed that identified structural variants affected synaptic vesicle endocytosis, cell leading-edge organization, and signaling for neurite outgrowth. The results further support the involvement of the regulation of neurotransmission, neuronal migration, and sound-sensing in GTS.
Topics: Humans; Tourette Syndrome; Male; Female; Pedigree; Genetic Predisposition to Disease; Extracellular Matrix Proteins; Adult; Whole Genome Sequencing
PubMed: 38891944
DOI: 10.3390/ijms25115758 -
International Journal of Molecular... May 2024Developmental and epileptic encephalopathy-9 (DEE9) is characterized by seizure onset in infancy, mild to severe intellectual impairment, and psychiatric features and is...
Developmental and epileptic encephalopathy-9 (DEE9) is characterized by seizure onset in infancy, mild to severe intellectual impairment, and psychiatric features and is caused by a mutation in the gene on chromosome Xq22. The rare, unusual X-linked type of disorder affects heterozygous females and mosaic males; transmitting males are unaffected. In our study, 165 patients with epilepsy were tested by Next Generation Sequencing (NGS)-based panel and exome sequencing using Illumina technology. screening identified three point mutations, one indel, and one 29 bp-long deletion in five unrelated female probands. Two novel mutations, c.1152_1180del (p.Gln385Serfs*6) and c.830_831delinsAA (p.Phe277*), were identified and found to be de novo pathogenic. Moreover, among the three inherited mutations, two originated from asymptomatic mothers and one from an affected father. The c.1682C>T and c.1711G>T mutations were present in the DNA samples of asymptomatic mothers. After targeted parental testing, X chromosome inactivation tests and Sanger sequencing were carried out for mosaicism examination on maternal saliva samples in the two asymptomatic mutation carrier subjects. Tissue mosaicism and X-inactivation tests were negative. Our results support the opportunity for reduced penetrance in DEE9 and contribute to expanding the genotype-phenotype spectrum of -related epilepsy.
Topics: Humans; Protocadherins; Female; Cadherins; Epilepsy; High-Throughput Nucleotide Sequencing; Mutation; Pedigree; Male; Child, Preschool; Child; Infant; Age of Onset
PubMed: 38891919
DOI: 10.3390/ijms25115732 -
Molecular Genetics & Genomic Medicine Jun 2024The Triggering Receptor Expressed on Myeloid Cells 2 protein (TREM2) plays a crucial role in various biological processes, including osteoclast differentiation, and... (Review)
Review
BACKGROUND
The Triggering Receptor Expressed on Myeloid Cells 2 protein (TREM2) plays a crucial role in various biological processes, including osteoclast differentiation, and disease-associated microglia (DAM) activation to regulate neuroinflammation, and phagocytosis in the brain. Genetic variations in TREM2 are implicated in neurodegenerative disorders, such as Nasu-hakola disease (NHD), characterized by bone lesions, neuropsychiatric disorders, and early-onset dementia.
METHODS
We studied 3 siblings with suspected NHD. Whole-exome sequencing was conducted on the proband to identify the possible genetic cause(s) and by Sanger sequencing to validate the identified variants in the two other affected siblings, a healthy sister, and the parents.
RESULTS
We identified a novel homozygous deletion (c.549del; p.(Leu184Serfs*5)) in TREM2. Our literature review reveals 16 TREM2 mutations causing early-onset dementia and bone lesions.
CONCLUSION
These findings, alongside previous research, elucidate the clinical spectrum of TREM2-related diseases, aiding accurate diagnosis and patient care. This knowledge is vital for understanding TREM2-dependent DAM and its involvement in the pathogenesis of neurodevelopmental disorders which can help to develop targeted therapies and improve outcomes for TREM2-affected individuals.
Topics: Female; Humans; Consanguinity; Homozygote; Lipodystrophy; Membrane Glycoproteins; Osteochondrodysplasias; Pedigree; Receptors, Immunologic; Siblings; Subacute Sclerosing Panencephalitis
PubMed: 38888203
DOI: 10.1002/mgg3.2476