scholarly journals Mutation Spectrum of the ABCA4 Gene in a Greek Cohort with Stargardt Disease: Identification of Novel Mutations and Evidence of Three Prevalent Mutated Alleles

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Kamakari Smaragda ◽  
Kokkinou Vassiliki ◽  
Koutsodontis George ◽  
Stamatiou Polixeni ◽  
Giatzakis Christoforos ◽  
...  

Aim. To evaluate the frequency and pattern of disease-associated mutations of ABCA4 gene among Greek patients with presumed Stargardt disease (STGD1). Materials and Methods. A total of 59 patients were analyzed for ABCA4 mutations using the ABCR400 microarray and PCR-based sequencing of all coding exons and flanking intronic regions. MLPA analysis as well as sequencing of two regions in introns 30 and 36 reported earlier to harbor deep intronic disease-associated variants was used in 4 selected cases. Results. An overall detection rate of at least one mutant allele was achieved in 52 of the 59 patients (88.1%). Direct sequencing improved significantly the complete characterization rate, that is, identification of two mutations compared to the microarray analysis (93.1% versus 50%). In total, 40 distinct potentially disease-causing variants of the ABCA4 gene were detected, including six previously unreported potentially pathogenic variants. Among the disease-causing variants, in this cohort, the most frequent was c.5714+5G>A representing 16.1%, while p.Gly1961Glu and p.Leu541Pro represented 15.2% and 8.5%, respectively. Conclusions. By using a combination of methods, we completely molecularly diagnosed 48 of the 59 patients studied. In addition, we identified six previously unreported, potentially pathogenic ABCA4 mutations.

2018 ◽  
Vol 2018 ◽  
pp. 1-1
Author(s):  
Smaragda Kamakari ◽  
Vassiliki Kokkinou ◽  
George Koutsodontis ◽  
Polixeni Stamatiou ◽  
Christoforos Giatzakis ◽  
...  

2019 ◽  
Vol 10 ◽  
Author(s):  
Fang-Yuan Hu ◽  
Jian-kang Li ◽  
Feng-Juan Gao ◽  
Yu-He Qi ◽  
Ping Xu ◽  
...  

2021 ◽  
Author(s):  
Elke M. van Veen ◽  
D. Gareth Evans ◽  
Elaine F. Harkness ◽  
Helen J. Byers ◽  
Jamie M. Ellingford ◽  
...  

AbstractPurpose: Lobular breast cancer (LBC) accounts for ~ 15% of breast cancer. Here, we studied the frequency of pathogenic germline variants (PGVs) in an extended panel of genes in women affected with LBC. Methods: 302 women with LBC and 1567 without breast cancer were tested for BRCA1/2 PGVs. A subset of 134 LBC affected women who tested negative for BRCA1/2 PGVs underwent extended screening, including: ATM, CDH1, CHEK2, NBN, PALB2, PTEN, RAD50, RAD51D, and TP53.Results: 35 PGVs were identified in the group with LBC, of which 22 were in BRCA1/2. Ten actionable PGVs were identified in additional genes (ATM(4), CDH1(1), CHEK2(1), PALB2(2) and TP53(2)). Overall, PGVs in three genes conferred a significant increased risk for LBC. Odds ratios (ORs) were: BRCA1: OR = 13.17 (95%CI 2.83–66.38; P = 0.0017), BRCA2: OR = 10.33 (95%CI 4.58–23.95; P < 0.0001); and ATM: OR = 8.01 (95%CI 2.52–29.92; P = 0.0053). We did not detect an increased risk of LBC for PALB2, CDH1 or CHEK2. Conclusion: The overall PGV detection rate was 11.59%, with similar rates of BRCA1/2 (7.28%) PGVs as for other actionable PGVs (7.46%), indicating a benefit for extended panel genetic testing in LBC. We also report a previously unrecognised association of pathogenic variants in ATM with LBC.


2020 ◽  
Vol 21 (10) ◽  
pp. 3430
Author(s):  
Aneta Ścieżyńska ◽  
Marta Soszyńska ◽  
Michał Komorowski ◽  
Anna Podgórska ◽  
Natalia Krześniak ◽  
...  

ABCA4 gene mutations are the cause of a spectrum of ABCA4 retinopathies, and the most common juvenile macular degeneration is called Stargardt disease. ABCA4 has previously been observed almost exclusively in the retina. Therefore, studying the functional consequences of ABCA4 variants has required advanced molecular analysis techniques. The aim of the present study was to evaluate whether human hair follicles may be used for molecular analysis of the ABCA4 gene splice-site variants in patients with ABCA4 retinopathies. We assessed ABCA4 expression in hair follicles and skin at mRNA and protein levels by means of real-time PCR and Western blot analyses, respectively. We performed cDNA sequencing to reveal the presence of full-length ABCA4 transcripts and analyzed ABCA4 transcripts from three patients with Stargardt disease carrying different splice-site ABCA4 variants: c.5312+1G>A, c.5312+2T>G and c.5836-3C>A. cDNA analysis revealed that c.5312+1G>A, c.5312+2T>G variants led to the skipping of exon 37, and the c.5836-3C>A variant resulted in the insertion of 30 nucleotides into the transcript. Our results strongly argue for the use of hair follicles as a model for the molecular analysis of the pathogenicity of ABCA4 variants in patients with ABCA4 retinopathies.


2019 ◽  
Vol 27 (2) ◽  
Author(s):  
M. Aronson ◽  
C. Swallow ◽  
A. Govindarajan ◽  
K. Semotiuk ◽  
Z. Cohen ◽  
...  

Background CDH1 pathogenic variants (PV) cause the majority of inherited diffuse-gastric cancer (DGC), but have low detection rates and vary geographically. This study examines hereditary causes of DGC in patients from Ontario, Canada. Methods Eligible DGC cases at the Zane Cohen Centre (ZCC) underwent multi-gene panel or CDH1 single-site testing if they met 2015 International Gastric Cancer Linkage Consortium (IGCLC) criteria, isolated DGC <50 or family history suggestive of an inherited cancer syndrome. A secondary aim was to review all CDH1 families at the ZCC to assess cancer penetrance. Results 85 DGC patients underwent CDH1 (n=43) or multi-gene panel testing (n=42), and 15 (17.6%) PV or likely PV were identified.  CDH1 detection rate was 9.4% (n=8/85), and 11% (n=7/65) using IGCLC criteria.  No CDH1 PV identified in isolated DGC <40, but one PV identified in isolated DGC<50.  Multi-gene panel from 42 individuals identified 9 PV (21.4%) including CDH1, STK11, ATM, BRCA2, MLH1 and MSH2.  Review of 81 CDH1 carriers revealed that 10% had DGC (median age:48, range:38-59), 41% were unaffected (median age:53, range:26-89).  Three families had lobular-breast cancer (LBC) only.  Non-DGC/LBC malignancies included colorectal, gynecological, kidney/bladder, prostate, testicular and ductal breast. Conclusions Low detection rate of CDH1 in Ontario DGC patients.  No CDH1 PV found in isolated DGC <40, but identified in isolated DGC<50. Multi-gene panels are recommended for all DGC under age 50, and those meeting the IGCLC criteria, given overlapping phenotype with other hereditary conditions. HDGC phenotype is evolving with a spectrum of non-DGC/LBC cancers.


2019 ◽  
Vol 32 (11) ◽  
pp. 1207-1215
Author(s):  
Babak Emamalizadeh ◽  
Yousef Daneshmandpour ◽  
Abbas Tafakhori ◽  
Sakineh Ranji-Burachaloo ◽  
Sajad Shafiee ◽  
...  

Abstract Background X-linked adrenoleukodystrophy (X-ALD), the most common peroxisomal disorder, is caused by mutations in the ABCD1 gene located on Xq28. X-ALD is characterized by a spectrum of different manifestations varying in patients and families. Methods Four pedigrees with X-ALD consisting of patients and healthy members were selected for investigation of ABCD1 gene mutations. The mutation analysis was performed by polymerase chain reaction (PCR) followed by direct sequencing of all exons. The identified mutations were investigated using bioinformatics tools to predict their effects on the protein product and also to compare the mutated sequence with close species. Results One previously known missense mutation (c.1978 C > T) and three novel mutations (c.1797dupT, c.879delC, c.1218 C > G) were identified in the ABCD1 gene, each in one family. Predicting the effects of the mutations on protein structure and function indicated the probable damaging effect for them with significant alterations in the protein structure. We found three novel mutations in the ABCD1 gene with damaging effects on its protein product and responsible for X-ALD.


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