Multisystem inflammatory syndrome in children (MIS-C) is a rare condition following SARS-CoV-2 infection associated with intestinal manifestations. Genetic predisposition, including inborn errors of the OAS-RNAseL pathway, has been reported. We sequenced 154 MIS-C patients and utilized a novel statistical framework of gene burden analysis, "burdenMC," which identified an enrichment for rare predicted-deleterious variants in BTNL8 (OR = 4.2, 95% CI: 3.5-5.3, P < 10-6). BTNL8 encodes an intestinal epithelial regulator of Vγ4+γδ T cells implicated in regulating gut homeostasis. Enrichment was exclusive to MIS-C, being absent in patients with COVID-19 or bacterial disease. Using an available functional test for BTNL8, rare variants from a larger cohort of MIS-C patients (n = 835) were tested which identified eight variants in 18 patients (2.2%) with impaired engagement of Vγ4+γδ T cells. Most of these variants were in the B30.2 domain of BTNL8 implicated in sensing epithelial cell status. These findings were associated with altered intestinal permeability, suggesting a possible link between disrupted gut homeostasis and MIS-C-associated enteropathy triggered by SARS-CoV-2.
- MeSH
- butyrofiliny * genetika metabolismus MeSH
- COVID-19 * genetika komplikace imunologie virologie MeSH
- dítě MeSH
- genetická predispozice k nemoci MeSH
- heterozygot MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- předškolní dítě MeSH
- SARS-CoV-2 * MeSH
- syndrom systémové zánětlivé reakce * genetika MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Corneal dystrophies are phenotypically and genetically heterogeneous, often resulting in visual impairment caused by corneal opacification. We investigated the genetic cause of an autosomal dominant corneal stromal dystrophy in a pedigree with eight affected individuals in three generations. Affected individuals had diffuse central stromal opacity, with reduced visual acuity in older family members. Histopathology of affected cornea tissue removed during surgery revealed mild stromal textural alterations with alcianophilic deposits. Whole genome sequence data were generated for four affected individuals. No rare variants (MAF < 0.001) were identified in established corneal dystrophy genes. However, a novel heterozygous missense variant in exon 4 of SPARCL1, NM_004684: c.334G > A; p.(Glu112Lys), which is predicted to be damaging, segregated with disease. SPARC-like protein 1 (SPARCL1) is a secreted matricellular protein involved in cell migration, cell adhesion, tissue repair, and remodelling. Interestingly, SPARCL1 has been shown to regulate decorin. Heterozygous variants in DCN, encoding decorin, cause autosomal dominant congenital stromal corneal dystrophy, suggesting a common pathogenic pathway. Therefore, we performed immunohistochemistry to compare SPARCL1 and decorin localisation in corneal tissue from an affected family member and an unaffected control. Strikingly, the level of decorin was significantly decreased in the corneal stroma of the affected tissue, and SPARCL1 appeared to be retained in the epithelium. In summary, we describe a novel autosomal dominant corneal stromal dystrophy associated with a missense variant in SPARCL1, extending the phenotypic and genetic heterogeneity of inherited corneal disease.
- MeSH
- dědičné dystrofie rohovky * genetika patologie MeSH
- dekorin genetika metabolismus MeSH
- dospělí MeSH
- extracelulární matrix - proteiny * genetika MeSH
- heterozygot MeSH
- lidé středního věku MeSH
- lidé MeSH
- missense mutace * MeSH
- proteiny vázající vápník * genetika MeSH
- rodokmen * MeSH
- senioři MeSH
- stroma rohovky patologie metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
INTRODUCTION: ALZ-801/valiltramiprosate is a small-molecule oral inhibitor of beta amyloid (Aβ) aggregation and oligomer formation being studied in a phase 2 trial in APOE4 carriers with early Alzheimer's disease (AD) to evaluate treatment effects on fluid and imaging biomarkers and cognitive assessments. METHODS: The single-arm, open-label phase 2 trial was designed to evaluate the effects of the ALZ-801 265 mg tablet taken twice daily (after 2 weeks once daily) on plasma fluid AD biomarkers, hippocampal volume (HV), and cognition over 104 weeks in APOE4 carriers. The study enrolled subjects aged 50-80 years, with early AD [Mini-Mental State Examination (MMSE) ≥ 22, Clinical Dementia Rating-Global (CDR-G) 0.5 or 1], apolipoprotein E4 (APOE4) genotypes including APOE4/4 and APOE3/4 genotypes, and positive cerebrospinal fluid (CSF) AD biomarkers or prior amyloid scans. The primary outcome was plasma p-tau181, HV evaluated by magnetic resonance imaging (MRI) was the key secondary outcome, and plasma Aβ42 and Aβ40 were the secondary biomarker outcomes. The cognitive outcomes were the Rey Auditory Verbal Learning Test and the Digit Symbol Substitution Test. Safety and tolerability evaluations included treatment-emergent adverse events and amyloid-related imaging abnormalities (ARIA). The study was designed and powered to detect 15% reduction from baseline in plasma p-tau181 at the 104-week endpoint. A sample size of 80 subjects provided adequate power to detect this difference at a significance level of 0.05 using a two-sided paired t-test. RESULTS: The enrolled population of 84 subjects (31 homozygotes and 53 heterozygotes) was 52% females, mean age 69 years, MMSE 25.7 [70% mild cognitive impairment (MCI), 30% mild AD] with 55% on cholinesterase inhibitors. Plasma p-tau181 reduction from baseline was significant (31%, p = 0.045) at 104 weeks and all prior visits; HV atrophy was significantly reduced (p = 0.0014) compared with matched external controls from an observational Early AD study. Memory scores showed minimal decline from baseline over 104 weeks and correlated significantly with decreased HV atrophy (Spearman's 0.44, p = 0.002). Common adverse events were COVID infection and mild nausea, and no drug-related serious adverse events were reported. Of 14 early terminations, 6 were due to nonserious treatment-emergent adverse events and 1 death due to COVID. There was no vasogenic brain edema observed on MRI over 104 weeks. CONCLUSIONS: The effect of ALZ-801 on reducing plasma p-tau181 over 2 years demonstrates target engagement and supports its anti-Aβ oligomer action that leads to a robust decrease in amyloid-induced brain neurodegeneration. The significant correlation between reduced HV atrophy and cognitive stability over 2 years suggests a disease-modifying effect of ALZ-801 treatment in patients with early AD. Together with the favorable safety profile with no events of vasogenic brain edema, these results support further evaluation of ALZ-801 in a broader population of APOE4 carriers, who represent two-thirds of patients with AD. TRIAL REGISTRATION: https://clinicaltrials.gov/study/NCT04693520 .
- MeSH
- Alzheimerova nemoc * farmakoterapie diagnostické zobrazování MeSH
- amyloidní beta-protein * MeSH
- aplikace orální MeSH
- apolipoprotein E4 * genetika MeSH
- biologické markery * krev MeSH
- heterozygot MeSH
- hipokampus * účinky léků diagnostické zobrazování MeSH
- kognice * účinky léků MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- peptidové fragmenty krev MeSH
- proteiny tau MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- klinické zkoušky, fáze II MeSH
BACKGROUND: X-linked nephrogenic diabetes insipidus (NDI) is a rare genetic renal disease caused by pathogenic variants in the AVPR2 gene. Single nucleotide variants and small insertions/deletions in AVPR2 are reliably detected by routine clinical sequencing. Nevertheless, structural variants involving AVPR2 are challenging to identify accurately by conventional genetic testing. Here, we report a novel deletion of AVPR2 in a Czech family identified for the first time by targeted long-read sequencing (T-LRS). METHODS: A male proband with X-linked NDI underwent clinical sequencing of the AVPR2 gene that failed and thus indicated possible whole-gene deletion. Therefore, PCR mapping and subsequent targeted long-read sequencing (T-LRS) using a Pacific Biosciences sequencer were applied to search for the suspected deletion. To validate the deletion breakpoints and prove variant segregation in the family with X-linked NDI, Sanger sequencing of the deletion junction was performed. Quantitative real-time PCR was further carried out to confirm the carrier status of heterozygous females. RESULTS: By T-LRS, a novel 7.5 kb deletion of AVPR2 causing X-linked NDI in the proband was precisely identified. Sanger sequencing of the deletion junction confirmed the variant breakpoints and detected the deletion in the probands ́ mother, maternal aunt, and maternal cousin with X-linked NDI. The carrier status in heterozygous females was further validated by quantitative real-time PCR. CONCLUSIONS: Identifying the 7.5 kb deletion gave a precise molecular diagnosis for the proband, enabled genetic counselling and genetic testing for the family, and further expanded the spectrum of structural variants causing X-linked NDI. Our results also show that T-LRS has significant potential for accurately identifying putative structural variants.
Patients with autoimmune polyendocrinopathy syndrome type 1 (APS-1) caused by autosomal recessive AIRE deficiency produce autoantibodies that neutralize type I interferons (IFNs)1,2, conferring a predisposition to life-threatening COVID-19 pneumonia3. Here we report that patients with autosomal recessive NIK or RELB deficiency, or a specific type of autosomal-dominant NF-κB2 deficiency, also have neutralizing autoantibodies against type I IFNs and are at higher risk of getting life-threatening COVID-19 pneumonia. In patients with autosomal-dominant NF-κB2 deficiency, these autoantibodies are found only in individuals who are heterozygous for variants associated with both transcription (p52 activity) loss of function (LOF) due to impaired p100 processing to generate p52, and regulatory (IκBδ activity) gain of function (GOF) due to the accumulation of unprocessed p100, therefore increasing the inhibitory activity of IκBδ (hereafter, p52LOF/IκBδGOF). By contrast, neutralizing autoantibodies against type I IFNs are not found in individuals who are heterozygous for NFKB2 variants causing haploinsufficiency of p100 and p52 (hereafter, p52LOF/IκBδLOF) or gain-of-function of p52 (hereafter, p52GOF/IκBδLOF). In contrast to patients with APS-1, patients with disorders of NIK, RELB or NF-κB2 have very few tissue-specific autoantibodies. However, their thymuses have an abnormal structure, with few AIRE-expressing medullary thymic epithelial cells. Human inborn errors of the alternative NF-κB pathway impair the development of AIRE-expressing medullary thymic epithelial cells, thereby underlying the production of autoantibodies against type I IFNs and predisposition to viral diseases.
- MeSH
- aktivační mutace MeSH
- autoprotilátky * imunologie MeSH
- COVID-19 genetika imunologie MeSH
- epiteliální buňky štítné žlázy metabolismus patologie MeSH
- genetická predispozice k nemoci * MeSH
- heterozygot MeSH
- interferon typ I * antagonisté a inhibitory imunologie MeSH
- kinasa indukující NF-kappaB MeSH
- lidé MeSH
- mutace ztráty funkce MeSH
- NF-kappa B - podjednotka p52 nedostatek genetika MeSH
- NF-kappa B * nedostatek genetika MeSH
- protein AIRE MeSH
- proteiny I-kappa B nedostatek genetika MeSH
- thymus abnormality imunologie patologie MeSH
- virová pneumonie genetika imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Nijmegen breakage syndrome (NBS) is an autosomal-recessive chromosome instability disorder characterized by, among others, hypersensitivity to X-irradiation and an exceptionally high risk for lymphoid malignancy. The vast majority of NBS patients is homozygous for a common Slavic founder mutation, c.657del5, of the NBN gene, which is involved in the repair of DNA double-strand breaks (DSBs). The founder mutation also predisposes heterozygous carriers to cancer, apparently however, with a higher risk in the Czech Republic/Slovakia (CS) than in Poland. AIM: To examine whether the age of cancer manifestation and cancer death of NBN homozygotes is different between probands from CS and Poland. METHODS: The study is restricted to probands born until 1989, before replacement of the communist regime by a democratic system in CS and Poland, and a substantial transition of the health care systems. Moreover, all patients were recruited without knowledge of their genetic status since the NBN gene was not identified until 1998. RESULTS: Here, we show that cancer manifestation of NBN homozygotes is at a significantly earlier age in probands from CS than from Poland. This is explained by the difference in natural and medical radiation exposure, though within the permissible dosage. CONCLUSION: It is reasonable to assume that this finding also sheds light on the higher cancer risk of NBN heterozygotes in CS than in Poland. This has implications for genetic counseling and individualized medicine also of probands with other DNA repair defects.
INTRODUCTION: Height, body mass index (BMI), and weight gain are associated with breast cancer risk in the general population. It is unclear whether these associations also exist for carriers of pathogenic variants in the BRCA1 or BRCA2 genes. PATIENTS AND METHODS: An international pooled cohort of 8091 BRCA1/2 variant carriers was used for retrospective and prospective analyses separately for premenopausal and postmenopausal women. Cox regression was used to estimate breast cancer risk associations with height, BMI, and weight change. RESULTS: In the retrospective analysis, taller height was associated with risk of premenopausal breast cancer for BRCA2 variant carriers (HR 1.20 per 10 cm increase, 95% CI 1.04-1.38). Higher young-adult BMI was associated with lower premenopausal breast cancer risk for both BRCA1 (HR 0.75 per 5 kg/m2, 95% CI 0.66-0.84) and BRCA2 (HR 0.76, 95% CI 0.65-0.89) variant carriers in the retrospective analysis, with consistent, though not statistically significant, findings from the prospective analysis. In the prospective analysis, higher BMI and adult weight gain were associated with higher postmenopausal breast cancer risk for BRCA1 carriers (HR 1.20 per 5 kg/m2, 95% CI 1.02-1.42; and HR 1.10 per 5 kg weight gain, 95% CI 1.01-1.19, respectively). CONCLUSION: Anthropometric measures are associated with breast cancer risk for BRCA1 and BRCA2 variant carriers, with relative risk estimates that are generally consistent with those for women from the general population.
- MeSH
- dospělí MeSH
- genetická predispozice k nemoci MeSH
- geny BRCA2 * MeSH
- heterozygot MeSH
- hmotnostní přírůstek genetika MeSH
- index tělesné hmotnosti MeSH
- lidé MeSH
- nádory prsu * epidemiologie genetika patologie MeSH
- protein BRCA1 genetika MeSH
- protein BRCA2 genetika MeSH
- retrospektivní studie MeSH
- riziko MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Pathogenic variants affecting the BLM gene are responsible for the manifestation of extremely rare cancer‐predisposing Bloom syndrome. The present study reports on a case of an infant with a congenital hypotrophy, short stature and abnormal facial appearance. Initially she was examined using a routine molecular diagnostic algorithm, including the cytogenetic analysis of her karyotype, microarray analysis and methylation‐specific MLPA, however, she remained undiagnosed on a molecular level. Therefore, she and her parents were enrolled in the project of trio‐based exome sequencing (ES) using Human Core Exome kit. She was revealed as a carrier of an extremely rare combination of causative sequence variants altering the BLM gene (NM_000057.4), c.1642C>T and c.2207_2212delinsTAGATTC in the compound heterozygosity, resulting in a diagnosis of Bloom syndrome. Simultaneously, a mosaic loss of heterozygosity of chromosome 11p was detected and then confirmed as a borderline imprinting center 1 hypermethylation on chromosome 11p15. The diagnosis of Bloom syndrome and mosaic copy‐number neutral loss of heterozygosity of chromosome 11p increases a lifetime risk to develop any types of malignancy. This case demonstrates the trio‐based ES as a complex approach for the molecular diagnostics of rare pediatric diseases.
- MeSH
- Bloomův syndrom * diagnóza genetika patologie MeSH
- dítě MeSH
- heterozygot MeSH
- kojenec MeSH
- lidé MeSH
- lidský chromozom Y MeSH
- mozaicismus MeSH
- sekvenování exomu MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
Acid-β-glucosidase (GCase, EC3.2.1.45), the lysosomal enzyme which hydrolyzes the simple glycosphingolipid, glucosylceramide (GlcCer), is encoded by the GBA1 gene. Biallelic mutations in GBA1 cause the human inherited metabolic disorder, Gaucher disease (GD), in which GlcCer accumulates, while heterozygous GBA1 mutations are the highest genetic risk factor for Parkinson's disease (PD). Recombinant GCase (e.g., Cerezyme® ) is produced for use in enzyme replacement therapy for GD and is largely successful in relieving disease symptoms, except for the neurological symptoms observed in a subset of patients. As a first step toward developing an alternative to the recombinant human enzymes used to treat GD, we applied the PROSS stability-design algorithm to generate GCase variants with enhanced stability. One of the designs, containing 55 mutations compared to wild-type human GCase, exhibits improved secretion and thermal stability. Furthermore, the design has higher enzymatic activity than the clinically used human enzyme when incorporated into an AAV vector, resulting in a larger decrease in the accumulation of lipid substrates in cultured cells. Based on stability-design calculations, we also developed a machine learning-based approach to distinguish benign from deleterious (i.e., disease-causing) GBA1 mutations. This approach gave remarkably accurate predictions of the enzymatic activity of single-nucleotide polymorphisms in the GBA1 gene that are not currently associated with GD or PD. This latter approach could be applied to other diseases to determine risk factors in patients carrying rare mutations.
- MeSH
- celulasy * genetika MeSH
- Gaucherova nemoc * farmakoterapie genetika MeSH
- heterozygot MeSH
- lidé MeSH
- mutace MeSH
- Parkinsonova nemoc * genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Congenital myasthenic syndromes (CMSs) are characterized by hypotonia, episodic apnea, muscle weakness, ptosis and generalized fatigability. CMS type 20 (CMS20) is a rare disorder caused by variants in SLC5A7. In contrast to most other CMSs, CMS20 is also associated with neurodevelopmental disorders (NDDs). Only 19 patients from 14 families have been reported so far. METHODS: We studied a 12-year-old boy with symptoms manifested at six weeks of age. Later, he also showed speech delay, moderate intellectual disability and autism. Analysis of CMS genes known at the time of clinical diagnosis yielded no results. Trio exome sequencing (ES) was performed. RESULTS: ES revealed compound heterozygosity for two SLC5A7 variants, p.(Asn431Lys) and p.(Ile291Thr). While the first variant was absent from all databases, the second variant has already been described in one patient. In silico analysis of known pathogenic SLC5A7 variants showed that variants with a higher predicted deleteriousness may be associated with earlier onset and increased severity of neuromuscular manifestations. CONCLUSION: Our patient confirms that CMS20 can be associated with NDDs. The study illustrates the strength of ES in deciphering the genetic basis of rare diseases, contributes to characterization of CMS20 and suggests trends in genotype-phenotype correlation in CMS20.
- MeSH
- genetické asociační studie MeSH
- heterozygot MeSH
- kongenitální myastenické syndromy * genetika diagnóza MeSH
- lidé MeSH
- mentální retardace * komplikace MeSH
- missense mutace MeSH
- symportéry * genetika MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
