scholarly journals Comprehensive Geno- and Phenotyping in a Complex Pedigree Including Four Different Inherited Retinal Dystrophies

Genes ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 137
Author(s):  
Johannes Birtel ◽  
Martin Gliem ◽  
Kristina Hess ◽  
Theresa H. Birtel ◽  
Frank G. Holz ◽  
...  

Inherited retinal dystrophies (IRDs) are characterized by high clinical and genetic heterogeneity. A precise characterization is desirable for diagnosis and has impact on prognosis, patient counseling, and potential therapeutic options. Here, we demonstrate the effectiveness of the combination of in-depth retinal phenotyping and molecular genetic testing in complex pedigrees with different IRDs. Four affected Caucasians and two unaffected relatives were characterized including multimodal retinal imaging, functional testing, and targeted next-generation sequencing. A considerable intrafamilial phenotypic and genotypic heterogeneity was identified. While the parents of the index family presented with rod-cone dystrophy and ABCA4-related retinopathy, their two sons revealed characteristics in the spectrum of incomplete congenital stationary night blindness and ocular albinism, respectively. Molecular testing revealed previously described variants in RHO, ABCA4, and MITF as well as a novel variant in CACNA1F. Identified variants were verified by intrafamilial co-segregation, bioinformatic annotations, and in silico analysis. The coexistence of four independent IRDs caused by distinct mutations and inheritance modes in one pedigree is demonstrated. These findings highlight the complexity of IRDs and underscore the need for the combination of extensive molecular genetic testing and clinical characterization. In addition, a novel variant in the CACNA1F gene is reported associated with incomplete congenital stationary night blindness.

Author(s):  
Hajar ARYAN ◽  
Atekeh BAHADORI ◽  
Dariush D. FARHUD ◽  
Marjan ZARIF YEGANEH ◽  
Haniyeh POURKALHOR

Oguchi disease is a rare autosomal recessive form of congenital stationary night blindness (CSNB) characterized by specific features such as golden-brown discoloration of the fundus called Mizuo-Nakamura phenomenon which is distinguishable by fundoscopy, and retinography. Clinical diagnosis is confirmed through genetic test. Two known genes in pathogenesis of Oguchi disease are SAG and GRK1. A 35-year-old Iranian male exhibiting the clinical features of congenital stationary night blindness, was referred to the genetic clinic of Dr. Farhud, Tehran, Iran in 2012 and examined. Ophthalmic examination including slit-lamp biomicroscopy, perimetry and funduscopy was performed. Additionally, the full-field electroretinography and molecular testing for congenital stationary night blindness were performed. Molecular genetic tests, including the analysis of GSK1 and SAG genes exon-intron boundaries were performed for this patient and his family. According to the sequencing results, we did not find any mutation in GSK1 gene. However, a new homozygote mutation at location chr2:233320735, c.517delC, p.P96LfsX28 was identified in exon four of SAG gene. This deletion causes a frame shift mutation, and premature stop codon that results in deletion of about 281 amino acid residues of S-antigen visual arrestin protein (from entire C-terminal). This mutation was also found in patient’s parents and one of his sister as heterozygote form. This is the first molecular evidence for SAG gene mutation in an Iranian family affected with Oguchi disease type 1. The identification of the new c.517delC, p.P96LfsX28 mutation in this family with Oguchi disease can confirm the pathogenicity of this variant.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Christina Zeitz ◽  
Cécile Méjécase ◽  
Mathilde Stévenard ◽  
Christelle Michiels ◽  
Isabelle Audo ◽  
...  

Autosomal dominant congenital stationary night blindness (adCSNB) is rare and results from altered phototransduction giving a Riggs type of electroretinogram (ERG) with loss of the rod a-wave and small b-waves. These patients usually have normal vision in light. Only few mutations in genes coding for proteins of the phototransduction cascade lead to this condition; most of these gene defects cause progressive rod-cone dystrophy. Mutation analysis of an adCSNB family with a Riggs-type ERG revealed a novel variant (c.155T>A p.Ile52Asn) in GNAT1 coding for the α-subunit of transducin, cosegregating with the phenotype. Domain predictions and 3D-modelling suggest that the variant does not affect the GTP-binding site as other GNAT1 adCSNB mutations do. It affects a predicted nuclear localization signal and a part of the first α-helix, which is distant from the GTP-binding site. The subcellular protein localization of this and other mutant GNAT1 proteins implicated in CSNB are unaltered in mammalian GNAT1 overexpressing cells. Our findings add a third GNAT1 mutation causing adCSNB and suggest that different pathogenic mechanisms may cause this condition.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 7022-7022 ◽  
Author(s):  
Daniel Aaron Pollyea ◽  
Tracy George ◽  
Kathryn M Foucar ◽  
Harry Paul Erba ◽  
Michael A. Thompson ◽  
...  

7022 Background: Recurrent mutations in AML-associated genes have prognostic value and may help guide treatment decisions. Molecular genetic testing patterns for AML in clinical practice are largely unknown. Previously the CONNECT MDS/AML Disease Registry (George et al. ASH 2016. Abstract 3548) showed suboptimal adherence to WHO 2008 recommendations for AML in a cohort of newly diagnosed (ND) AML patients (pts) in clinical practice. Here we report a detailed analysis of patterns of molecular genetic testing in pts with ND AML in community and academic settings. Methods: The CONNECT MDS/AML Disease Registry (NCT01688011) is a US prospective, observational cohort study of pts with ND AML (≥55 years) or MDS. Enrollment is ongoing. All clinical decisions are made by study clinicians. The current analysis evaluated the percentage of pts with AML with molecular genetic testing recommended by NCCN guidelines ( NPM1, FLT3-ITD, CEBPA, IDH1, IDH2, DNMT3A, and KIT). Chi-square tests evaluated effects of several variables on likelihood of molecular genetic testing. Results: Between 12 Dec 2013, and 8 Dec 2016 (data cutoff), 259 AML pts were enrolled at 86 sites. Molecular genetic testing was reported in 67% (173/259) of pts. Likelihood of testing varied, respectively, for academic vs community sites (76% [70/92] vs 62% [103/167], P= .018), normal vs abnormal karyotype (77% [79/103] vs 59% [79/133], P= .006), age < 65 vs ≥65 (83% [65/78] vs 60% [108/181], P= .0003), and Medicare vs other insurance (61% [83/137] vs 74% [90/122], P= .025). In pts with molecular genetic testing (n = 173), the mutations tested varied substantially. All of the NCCN-recommended molecular genetic tests were reported in 9% (15/173) of pts, including 8% (6/79) of those with normal karyotype. Of the 7 NCCN-recommended tests, NPM1 (77%) and FLT3-ITD (76%) were most often reported and DNM T3A least often (16%). Conclusions: Early data from the CONNECT MDS/AML Disease Registry reveal that despite molecular testing reported in 67% of ND AML pts, a majority do not receive guideline-recommended testing. This prospective registry is uniquely positioned to capture changes in testing patterns as guidelines are established.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Michalis Georgiou ◽  
Naser Ali ◽  
Elizabeth Yang ◽  
Parampal S. Grewal ◽  
Tryfon Rotsos ◽  
...  

Abstract Purpose To present the detailed retinal phenotype of patients with Leber Congenital Amaurosis/Early-Onset Severe Retinal Dystrophy (LCA/EOSRD) caused by sequence variants in four genes, either not (n = 1) or very rarely (n = 3) previously associated with the disease. Methods Retrospective case series of LCA/EOSRD from four pedigrees. Chart review of clinical notes, multimodal retinal imaging, electrophysiology, and molecular genetic testing at a single tertiary referral center (Moorfields Eye Hospital, London, UK). Results The mean age of presentation was 3 months of age, with disease onset in the first year of life in all cases. Molecular genetic testing revealed the following disease-causing variants: PRPF8 (heterozygous c.5804G > A), PRPH2 (homozygous c.620_627delinsTA, novel variant), RP1 (homozygous c.4147_4151delGGATT, novel variant) and RPGR (heterozygous c.1894_1897delGACA). PRPF8, PRPH2, and RP1 variants have very rarely been reported, either as unique cases or case reports, with limited clinical data presented. RPGR variants have not previously been associated with LCA/EOSRD. Clinical history and detailed retinal imaging are presented. Conclusions The reported cases extend the phenotypic spectrum of PRPF8-, PRPH2-, RP1-, and RPGR-associated disease, and the genotypic spectrum of LCA/EOSRD. The study highlights the importance of retinal and functional phenotyping, and the importance of specific genetic diagnosis to potential future therapy.


2021 ◽  
pp. 337-343
Author(s):  
Eugenie Mok ◽  
Ka Wai Kam ◽  
Anthony J. Aldave ◽  
Alvin L. Young

A 65-year-old man presented with bilateral, painless, progressive blurring of vision over 9 years. Slit-lamp examination revealed bilateral subepithelial corneal opacities in clusters located at the mid-periphery. Anterior segment optical coherence tomography, in vivo confocal microscopy (IVCM), serum protein electrophoresis, and molecular genetic testing were performed to evaluate the cause of corneal opacities. Anterior segment optical coherence tomography revealed a band-like, hyperreflective lesion in the Bowman layer and anterior stroma of both corneas. IVCM revealed hyperreflective deposits in the epithelium, anterior stroma, and endothelium. Serum protein electrophoresis identified the presence of paraproteins (immunoglobulin kappa), and molecular genetic testing revealed absence of mutations in the transforming growth factor beta-induced gene (<i>TGFBI</i>) and collagen type XVII alpha 1 gene (<i>COL17A1</i>). The ocular diagnosis of paraproteinemic keratopathy eventually led to a systemic diagnosis of monoclonal gammopathy of undetermined significance by our hematologist/oncologist. Paraproteinemic keratopathy is a rare differential diagnosis in patients with bilateral corneal opacities and therefore may be misdiagnosed as corneal dystrophy or neglected as scars. In patients with bilateral corneal opacities of unknown cause, serological examination, adjunct anterior segment imaging, and molecular genetic testing play a role in establishing the diagnosis.


2017 ◽  
Vol 141 (10) ◽  
pp. 1342-1393 ◽  
Author(s):  
Daniel A. Arber ◽  
Michael J. Borowitz ◽  
Melissa Cessna ◽  
Joan Etzell ◽  
Kathryn Foucar ◽  
...  

Context.— A complete diagnosis of acute leukemia requires knowledge of clinical information combined with morphologic evaluation, immunophenotyping and karyotype analysis, and often, molecular genetic testing. Although many aspects of the workup for acute leukemia are well accepted, few guidelines have addressed the different aspects of the diagnostic evaluation of samples from patients suspected to have acute leukemia. Objective.— To develop a guideline for treating physicians and pathologists involved in the diagnostic and prognostic evaluation of new acute leukemia samples, including acute lymphoblastic leukemia, acute myeloid leukemia, and acute leukemias of ambiguous lineage. Design.— The College of American Pathologists and the American Society of Hematology convened a panel of experts in hematology and hematopathology to develop recommendations. A systematic evidence review was conducted to address 6 key questions. Recommendations were derived from strength of evidence, feedback received during the public comment period, and expert panel consensus. Results.— Twenty-seven guideline statements were established, which ranged from recommendations on what clinical and laboratory information should be available as part of the diagnostic and prognostic evaluation of acute leukemia samples to what types of testing should be performed routinely, with recommendations on where such testing should be performed and how the results should be reported. Conclusions.— The guideline provides a framework for the multiple steps, including laboratory testing, in the evaluation of acute leukemia samples. Some aspects of the guideline, especially molecular genetic testing in acute leukemia, are rapidly changing with new supportive literature, which will require on-going updates for the guideline to remain relevant.


Channels ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 17-33 ◽  
Author(s):  
D. M. Waldner ◽  
N. C. Giraldo Sierra ◽  
S. Bonfield ◽  
L. Nguyen ◽  
I. S. Dimopoulos ◽  
...  

2003 ◽  
Vol 127 (12) ◽  
pp. 1565-1572
Author(s):  
Susan H. Bernacki ◽  
Daniel H. Farkas ◽  
Wenmei Shi ◽  
Vivian Chan ◽  
Yenbou Liu ◽  
...  

Abstract Context.—Bioelectronic sensors, which combine microchip and biological components, are an emerging technology in clinical diagnostic testing. An electronic detection platform using DNA biochip technology (eSensor) is under development for molecular diagnostic applications. Owing to the novelty of these devices, demonstrations of their successful use in practical diagnostic applications are limited. Objective.—To assess the performance of the eSensor bioelectronic method in the validation of 6 Epstein-Barr virus–transformed blood lymphocyte cell lines with clinically important mutations for use as sources of genetic material for positive controls in clinical molecular genetic testing. Two cell lines carry mutations in the CFTR gene (cystic fibrosis), and 4 carry mutations in the HFE gene (hereditary hemochromatosis). Design.—Samples from each cell line were sent for genotype determination to 6 different molecular genetic testing facilities, including the laboratory developing the DNA biochips. In addition to the bioelectronic method, at least 3 different molecular diagnostic methods were used in the analysis of each cell line. Detailed data were collected from the DNA biochip output, and the genetic results were compared with those obtained using the more established methods. Results.—We report the successful use of 2 applications of the bioelectronic platform, one for detection of CFTR mutations and the other for detection of HFE mutations. In all cases, the results obtained with the DNA biochip were in concordance with those reported for the other methods. Electronic signal output from the DNA biochips clearly differentiated between mutated and wild-type alleles. This is the first report of the use of the cystic fibrosis detection platform. Conclusions.—Bioelectronic sensors for the detection of disease-causing mutations performed well when used in a “real-life” situation, in this case, a validation study of positive control blood lymphocyte cell lines with mutations of public health importance. This study illustrates the practical potential of emerging bioelectronic DNA detection technologies for use in current molecular diagnostic applications.


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