scholarly journals Three Patients With Disseminated Mycobacterial Infections Due to Severe Defects in Interferon Gamma Receptor Signaling: A Challenging Diagnosis

2021 ◽  
Author(s):  
Zijun Zhou ◽  
Iris H.I.M. Hollink ◽  
Arjan Bouman ◽  
Mirthe S. Lourens ◽  
Rik A. Brooimans ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Compound Heterozygous ◽  
Mycobacterial Infections ◽  
Susceptibility To Infection ◽  
Gamma Receptor ◽  
Alu Insertion ◽  
Whole Exome ◽  
Novel Variant ◽  
Ifn Γ

Abstract IFN–gamma receptor (IFNGR) signaling via STAT1 is crucial in the defense against intracellular pathogens. Defects in this pathway enhance the susceptibility to infection by otherwise weak pathogenic mycobacteria, resulting in a primary immunodeficiency called mendelian susceptibility to mycobacterial disease (MSMD). Here we describe three patients with MSMD caused by variants in the IFNGR1 or STAT1 genes. All three patients presented with disseminated non-tuberculous mycobacterial infections caused by M. avium , M. persicum or M. bovis BCG respectively. Whole-exome sequencing (WES) was used as the first line diagnostic approach, however in all patients additional analysis was crucial to make the definite diagnosis. In Patient 1, only one heterozygous autosomal recessive variant p.(Val63Gly) in the IFNGR1 gene was identified. Patient 2 was compound heterozygous for the pathogenic null p.(Val68Lysfs*6) variant and the hypomorphic p.(Ile37Thr) variant in IFNGR1. In Patient 3 a novel variant in the STAT1 gene c.1379A>T, p.(Asn460Ile) was identified. Additional genetic analysis identified a second novel complex Alu-insertion in the IFNGR1 gene in Patient 1. Functional analysis showed that Patients 1 and 2 had reduced expression of IFNGR1. All patients had reduced phosphorylation of STAT1 and absent induction of SOCS1 mRNA after IFN-γ stimulation. While STAT1 phosphorylation was normal after IFN–α stimulation in Patient 1 and 2, it was mildly reduced in Patient 3. We conclude that functional assays are crucial to assess the extent of IFNGR signaling defects when new combinations of bi-allelic or non-conclusive genetic variants are found, which is important in the determination of clinical treatment.

scholarly journals Three patients with defects in interferon gamma receptor signaling: a challenging diagnosis

2021 ◽  
Author(s):  
Zijun Zhou ◽  
Iris Hollink ◽  
Arjan Bouman ◽  
Mirthe Lourens ◽  
Rik Brooimans ◽  
...  
Keyword(s):  
Snp Array ◽  
Compound Heterozygous ◽  
Susceptibility To Infection ◽  
Gamma Receptor ◽  
Alu Insertion ◽  
Whole Exome ◽  
Novel Variant ◽  
Diagnosis Method ◽  
Ifn Γ ◽  
Long Range Pcr

Background: Defects in IFN–gamma receptor (IFN-γR) signaling via STAT1 leads to susceptibility to infection by otherwise weak pathogenic mycobacteria, resulting in mendelian susceptibility to mycobacterial disease. We identified three patients presented with disseminated mycobacterial infections caused by M. avium, M. persicum or M. bovis BCG respectively. Whole-exome sequencing (WES) was used as the first line diagnostic approach, however in all patients additional analysis was crucial to make the definite diagnosis. Method: WES, SNP array and long range PCR were performed to identify the genetic defects. Expression of IFNGR1, STAT1, CD64, SOCS1 and phosphorylation of STAT1 were determined after stimulation with IFN-α or IFN-γ. Results: In Patient 1, only one heterozygous variant p.(Val63Gly) in the IFNGR1 gene was identified by WES. Additional genetic analysis identified a second complex Alu-insertion in IFNGR1. Patient 2 was compound heterozygous for the null p.(Val68Lysfs*6) variant and the hypomorphic p.(Ile37Thr) variant in IFNGR1. In Patient 3 a novel variant in the STAT1 gene p.(Asn460Ile) was identified. Patients 1 and 2 had reduced expression of IFN-γR1. All patients had reduced phosphorylation of STAT1 and absent induction of SOCS1 after IFN-γ stimulation. While STAT1 phosphorylation was normal after IFN–α stimulation in Patient 1 and 2, and mildly reduced in Patient 3. Conclusion: We conclude that functional assays are crucial to assess the extent of IFN-γR signaling defects when new combinations of bi-allelic or non-conclusive genetic variants are found, which is important in the determination of clinical treatment.

scholarly journals Three Novel Variants of CEP290 and CC2D2DA and a Link Between ZNF77 and SHH Signaling Pathway Are Found in Two Meckel-Gruber Syndrome Fetuses

2022 ◽  
Author(s):  
Zhidan Hong ◽  
Xuanyi He ◽  
Fang Yu ◽  
Huanyu Liu ◽  
Xiaoli Zhang ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Pathological Examination ◽  
Compound Heterozygous ◽  
Over Expression ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
The Family ◽  
Novel Variants ◽  
Novel Variant ◽  
Missed Diagnosis

AbstractMeckel-Gruber syndrome (MKS) is a rare lethal autosomal recessive inherited disorder. Missed diagnosis might happen in clinical works due to an unclear genotype–phenotype correlation. We analyzed two families visiting our center; the parents are normal; each of the family aborted a fetus at 12WG. Following ultrasonography and pathological examination, both were diagnosed as MKS. Whole exome sequencing identified a compound heterozygous of two novel variants of CEP290 and a heterozygous of a novel variant of CC2D2A. Frameshift mutations in ZNF77 were also detected. Western blot analyzing whole-brain tissue showed that the expression of ZNF77, CC2D2A, and CEP290 was enhanced. HEK293T transfected with over-expression wildtype/mutated ZNF77 plasmid showed that SHH was increased in wildtype ZNF77 cells, while SHH and CC2D2A were increased in mutated ZNF77 cells. Our research provided two novel pathogenic variants of CEP290 and CC2D2A and suggested that ZNF77 might promote the expression of CC2D2A and regulate the amount of SHH.

scholarly journals Gain-of-function human STAT1 mutations impair IL-17 immunity and underlie chronic mucocutaneous candidiasis

2011 ◽  
Vol 208 (8) ◽  
pp. 1635-1648 ◽  
Author(s):  
Luyan Liu ◽  
Satoshi Okada ◽  
Xiao-Fei Kong ◽  
Alexandra Y. Kreins ◽  
Sophie Cypowyj ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Coiled Coil ◽  
Cellular Responses ◽  
Chronic Mucocutaneous Candidiasis ◽  
Loss Of Function ◽  
Gain Of Function ◽  
Mucocutaneous Candidiasis ◽  
Coiled Coil Domain ◽  
Whole Exome ◽  
Ifn Γ

Chronic mucocutaneous candidiasis disease (CMCD) may be caused by autosomal dominant (AD) IL-17F deficiency or autosomal recessive (AR) IL-17RA deficiency. Here, using whole-exome sequencing, we identified heterozygous germline mutations in STAT1 in 47 patients from 20 kindreds with AD CMCD. Previously described heterozygous STAT1 mutant alleles are loss-of-function and cause AD predisposition to mycobacterial disease caused by impaired STAT1-dependent cellular responses to IFN-γ. Other loss-of-function STAT1 alleles cause AR predisposition to intracellular bacterial and viral diseases, caused by impaired STAT1-dependent responses to IFN-α/β, IFN-γ, IFN-λ, and IL-27. In contrast, the 12 AD CMCD-inducing STAT1 mutant alleles described here are gain-of-function and increase STAT1-dependent cellular responses to these cytokines, and to cytokines that predominantly activate STAT3, such as IL-6 and IL-21. All of these mutations affect the coiled-coil domain and impair the nuclear dephosphorylation of activated STAT1, accounting for their gain-of-function and dominance. Stronger cellular responses to the STAT1-dependent IL-17 inhibitors IFN-α/β, IFN-γ, and IL-27, and stronger STAT1 activation in response to the STAT3-dependent IL-17 inducers IL-6 and IL-21, hinder the development of T cells producing IL-17A, IL-17F, and IL-22. Gain-of-function STAT1 alleles therefore cause AD CMCD by impairing IL-17 immunity.

3-M syndrome – a primordial short stature disorder with novel CUL7 mutation in two Indian patients

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Radha Rama Devi Akella
Keyword(s):  
Short Stature ◽  
Autosomal Recessive ◽  
Genetic Diagnosis ◽  
Autosomal Recessive Disorder ◽  
Missense Variant ◽  
Postnatal Growth ◽  
Compound Heterozygous ◽  
Case Presentation ◽  
Whole Exome ◽  
Heterozygous Variant

Abstract Objective To evaluate the cause of short stature in children. Case presentation Two children with suspected skeletal dysplasia and short stature were evaluated. Conclusions The 3-M syndrome is a primordial growth disorder manifesting severe postnatal growth restriction, skeletal anomalies and prominent fleshy heels. The 3-M syndrome is a genetically heterogeneous disorder and the phenotype is similar. This is a rare autosomal recessive disorder with normal intellect. Two affected children have been identified by whole-exome sequencing. One patient harboured a compound heterozygous variant and the other was a homozygous missense variant. The genetic diagnosis helped in counselling the families and facilitated prenatal diagnosis in one (case 1) family.

scholarly journals Novel bi-allelic variants expand the SPTBN4-related genetic and phenotypic spectrum

2021 ◽  
Author(s):  
Markus Buelow ◽  
David Süßmuth ◽  
Laurie D. Smith ◽  
Omid Aryani ◽  
Claudia Castiglioni ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Neurodevelopmental Disorder ◽  
Neurological Dysfunction ◽  
Compound Heterozygous ◽  
Histochemical Analysis ◽  
Human Phenotype ◽  
Epileptiform Discharges ◽  
Whole Exome ◽  
Muscle Histology ◽  
Compound Heterozygous Variants

AbstractNeurodevelopmental disorder with hypotonia, neuropathy, and deafness (NEDHND, OMIM #617519) is an autosomal recessive disease caused by homozygous or compound heterozygous variants in SPTBN4 coding for type 4 βIV-spectrin, a non-erythrocytic member of the β-spectrin family. Variants in SPTBN4 disrupt the cytoskeletal machinery that controls proper localization of ion channels and the function of axonal domains, thereby generating severe neurological dysfunction. We set out to analyze the genetic causes and describe the clinical spectrum of suspected cases of NEDHND. Variant screening was done by whole exome sequencing; clinical phenotypes were described according to the human phenotype ontology, and histochemical analysis was performed with disease-specific antibodies. We report four families with five patients harboring novel homozygous and compound heterozygous SPTBN4 variants, amongst them a multi-exon deletion of SPTBN4. All patients presented with the key features of NEDHND; severe muscular hypotonia, dysphagia, absent speech, gross motor, and mental retardation. Additional symptoms comprised horizontal nystagmus, epileptiform discharges in EEG without manifest seizures, and choreoathetosis. Muscle histology revealed both characteristics of myopathy and of neuropathy. This report expands the SPTBN4 variant spectrum, highlights the spectrum of morphological phenotypes of NEDHND-patients, and reveals clinical similarities between the NEDHND, non-5q SMA, and congenital myopathies.

scholarly journals Two novel compound heterozygous variants of LTBP4 in a Chinese infant with cutis laxa type IC and a review of the related literature

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Qiang Zhang ◽  
Zailong Qin ◽  
Shang Yi ◽  
Hao Wei ◽  
Xun Zhao Zhou ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Retinal Hemorrhage ◽  
Cutis Laxa ◽  
Compound Heterozygous ◽  
Case Presentation ◽  
Whole Exome ◽  
Analytical Review ◽  
Different Populations ◽  
Compound Heterozygous Variants ◽  
Chromosome 19Q13

Abstract Background Autosomal recessive cutis laxa type IC (ARCL IC, MIM: #613177) results from a mutation in the LTBP4 gene (MIM: #604710) on chromosome 19q13. Case presentation A 28-day-old Chinese infant with generalized cutis laxa accompanied by impaired pulmonary, gastrointestinal, genitourinary, retinal hemorrhage, abnormality of coagulation and hyperbilirubinemia was admitted to our hospital. To find out the possible causes of these symptoms, whole-exome sequencing was performed on the infant. Two novel pathogenic frame-shift variants [c.605_606delGT (p.Ser204fs * 8) and c.1719delC (p.Arg574fs * 199)] of the LTBP4 gene associated with ARCL IC were found which was later verified by Sanger sequencing. The pathogenicity of mutations was subsequently assessed by several software programs and databases. In addition, an analytical review on the clinical phenotypes of the disease previously reported in literature was performed. Conclusions This is the first report of a Chinese infant with ARCL IC in China due to novel pathogenic variations of LTBP4. Our study extends the cutis laxa type IC mutation spectrum as well as the phenotypes associated with the disease in different populations.

scholarly journals Homozygous truncating NEK10 mutation, associated with primary ciliary dyskinesia: a case report

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Fuad Al Mutairi ◽  
Randa Alkhalaf ◽  
Abdullah Alkhorayyef ◽  
Fayhan Alroqi ◽  
Alyafee Yusra ◽  
...  
Keyword(s):  
Primary Ciliary Dyskinesia ◽  
Autosomal Recessive ◽  
Autosomal Recessive Disorder ◽  
Molecular Testing ◽  
Case Presentation ◽  
Immotile Cilia ◽  
Whole Exome ◽  
Novel Variant ◽  
Pathophysiological Aspect ◽  
Ciliary Dyskinesia

Abstract Background Primary Ciliary Dyskinesia (PCD) is also known as immotile-cilia syndrome, an autosomal recessive disorder of ciliary function, leading to mucus retention in the respiratory system in childhood. Our knowledge in the pathophysiological aspect of this devastating disorder is increasing with the advancement of genetic and molecular testing. Case presentation Here in, we report two siblings with a classical clinical and radiological presentation of PCD. Using whole exome sequencing we identified a homozygous truncating variant (c.3402 T > A); p.(Tyr1134*) in the NEK10 gene. Western bolt analysis revealed a decrease in the expression of NEK10 protein in the patient cells. Conclusions NEK10 plays a central role in the post-mitotic process of cilia assembly, regulating ciliary length and functions during physiological and pathological status. This study highlights the challenges of identifying disease-causing variants for a highly heterogeneous disorder and reports on the identification of a novel variant in NEK10 which recently associated with PCD.

scholarly journals Rapid Trio Exome Sequencing for Autosomal Recessive Renal Tubular Dysgenesis in Recurrent Oligohydramnios

2021 ◽  
Vol 12 ◽  
Author(s):  
Shin-Yu Lin ◽  
Gwo-Tsann Chuang ◽  
Chien-Hui Hung ◽  
Wei-Chou Lin ◽  
Yung-Ming Jeng ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Neonatal Death ◽  
Autosomal Recessive ◽  
Compound Heterozygous Mutation ◽  
Heterozygous Mutation ◽  
Compound Heterozygous ◽  
Early Neonatal Death ◽  
Renal Tubular Dysgenesis ◽  
Whole Exome ◽  
Renal Tubular

Oligohydramnios is not a rare prenatal finding. However, recurrent oligohydramnios is uncommon, and genetic etiology should be taken into consideration. We present two families with recurrent fetal oligohydramnios that did not respond to amnioinfusion. Rapid trio-whole-exome sequencing (WES) revealed mutations in the AGT gene in both families within 1 week. The first family had a compound heterozygous mutation with c.856 + 1G > T and c.857-619_1269 + 243delinsTTGCCTTGC changes. The second family had homozygous c.857-619_1269 + 243delinsTTGCCTTGC mutations. AGT gene mutation may lead to autosomal recessive renal tubular dysgenesis, a rare and lethal disorder that can result in early neonatal death. Both the alleles identified are known alleles associated with pathogenicity. Our findings suggest that trio-WES analysis may help rapidly identify causative etiologies that can inform prompt counseling and decision-making prenatally.

scholarly journals Whole-exome sequencing reveals POLR3B variants associated with progeria-related Wiedemann-Rautenstrauch syndrome

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Shao-Wen Wu ◽  
Lin Li ◽  
Fan Feng ◽  
Li Wang ◽  
Yuan-Yuan Kong ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Autosomal Recessive ◽  
Postnatal Growth ◽  
Compound Heterozygous ◽  
Congenital Dislocation ◽  
Case Presentation ◽  
Whole Exome ◽  
Compound Heterozygous Variants ◽  
Dislocation Of The Hip

Abstract Background Wiedemann-Rautenstrauch syndrome (WRS) is a rare autosomal recessive neonatal progeroid disorder characterized by prenatal and postnatal growth retardation, short stature, a progeroid appearance, hypotonia, and mental impairment. Case presentation A 6-year-old patient, who initially presented with multiple postnatal abnormalities, facial dysplasia, micrognathia, skull appearance, hallux valgus, and congenital dislocation of the hip, was recruited in this study. The patient was initially diagnosed with progeria. The mother of the patient had abnormal fetal development during her second pregnancy check-up, and the clinical phenotype of the fetus was similar to that of the patient. Whole-exome sequencing (WES) of the patient was performed, and POLR3B compound heterozygous variants—c.2191G > C:p.E731Q and c.3046G > A:p.V1016M—were identified in the patient. Using Sanger sequencing, we found that the phenotypes and genotypes were segregated within the pedigree. These two variants are novel and not found in the gnomAD and 1000 Genomes databases. The two mutation sites are highly conserved between humans and zebrafish. Conclusions Our study not only identified a novel WRS-associated gene, POLR3B, but also broadened the mutational and phenotypic spectra of POLR3B. Furthermore, WES may be useful for identifying rare disease-related genetic variants.

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