scholarly journals A novel PKHD1 mutation identified in a family affected by ARPKD Ling Hou, Yue Du, Chengguang Zhao, Yubin Wu

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Ling Hou ◽  
Yue Du ◽  
Chengguang Zhao ◽  
Yubin Wu

Objective Autosomal recessive polycystic kidney disease (ARPKD) is a rare inherited renal cystic disease involving multiple organs. It is caused by mutations in the PKHD1 gene. Here, we investigate the gene mutations in a family affected by ARPKD. Methods Genomic DNA was extracted from peripheral blood leukocytes obtained from the subjects, by means of targeted gene capture and next generation sequencing technologies for mutation screening, and were confirmed by Sanger sequencing. Results Two heterozygous mutations of PKHD1, c.6890T>C (p.Ile2297Thr) and c.11215C>T (p.Arg3739Trp), located in exons 43 and 62, respectively, were identified in the patient. Furthermore, the father and mother were revealed to be carriers of heterozygous c.6890T>C (p.Ile2297Thr) and c.11215C>T (p.Arg3739Trp) mutations, respectively. Mutation of c.11215C>T (p.Arg3739Trp) has been found in the ARPKD Mutation Database (http://www.humgen.rwth-aachen.de) but mutation of c.6890T>C (p.Ile2297Thr) has not been reported. Conclusions Compound heterozygous PKHD1 mutations were elucidated to be the molecular basis of ARPKD in this patient. The newly identified c.6890T>C (p.Ile2297Thr) mutation in the patient expands the mutation spectrum of the PKHD1 gene. Targeted gene capture and next generation sequencing are suitable for genetic diagnosis of single-gene inherited diseases like ARPKD, in which the pathogenic gene is large.

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Pengcheng Xu ◽  
Jun Xu ◽  
Hu Peng ◽  
Tao Yang

Genetic hearing loss is a common sensory disorder, and its cause is highly heterogeneous. In this study, by targeted next-generation sequencing of 414 known deafness genes, we identified compound heterozygous mutations p.R34X/p.M413T in TMC1 and p.S3417del/p.R1407T in MYO15A in two recessive Chinese Han deaf families. Intrafamilial cosegregation of the mutations with the hearing phenotype was confirmed in both families by the Sanger sequencing. Auditory features of the affected individuals are consistent with that previously reported for recessive mutations in TMC1 and MYO15A. The two novel mutations identified in this study, p.M413T in TMC1 and p.R1407T in MYO15A, are classified as likely pathogenic according to the guidelines of ACMG. Our study expanded the mutation spectrums of TMC1 and MYO15A and illustrated that genotype-phenotype correlation in combination with next-generation sequencing may improve the accuracy for genetic diagnosis of deafness.


2022 ◽  
pp. 1-11
Author(s):  
Selma Demir ◽  
Hümeyra Yaşar Köstek ◽  
Aslıhan Sanrı ◽  
Ruken Yıldırım ◽  
Fatma Özgüç Çömlek ◽  
...  

<b><i>Introduction:</i></b> Germline pathogenic variations of the genes encoding the components of the Ras-MAPK pathway are found to be responsible for RASopathies, a clinically and genetically heterogeneous group of diseases. In this study, we aimed to present the results of patients genetically investigated for RASopathy-related mutations in our Genetic Diagnosis Center. <b><i>Methods:</i></b> The results of 51 unrelated probands with RASopathy and 4 affected relatives (31 male, 24 female; mean age: 9.327 ± 8.214) were included in this study. Mutation screening was performed on DNA samples from peripheral blood of the patients either by Sanger sequencing of <i>PTPN11</i> hotspot regions (10/51 probands), or by a targeted amplicon next-generation sequencing panel (41/51 probands) covering the exonic regions of <i>BRAF</i>, <i>CBL</i>, <i>HRAS</i>, <i>KRAS</i>, <i>LZTR1</i>, <i>MAP2K1</i>, <i>MAP2K2</i>, <i>NF1</i>, <i>NRAS</i>, <i>PTPN11</i>, <i>RAF1</i>, <i>RASA2</i>, <i>RIT1</i>, <i>SHOC2</i>, <i>SOS1</i>, <i>SOS2</i>, <i>SPRED1</i>, and <i>KAT6B</i> genes. <b><i>Results:</i></b> Pathogenic/likely pathogenic variations found in 22 out of 51 probands (43.13%) and their 4 affected family members were located in <i>PTPN11</i>, <i>BRAF</i>, <i>KRAS</i>, <i>NF1</i>, <i>RAF1</i>, <i>SOS1</i>, and <i>SHOC2</i> genes. The c.148A&#x3e;C (p.Thr50Pro) variation in the <i>KRAS</i> gene was a novel variant detected in a sibling in our patient cohort. We found supportive evidence for the pathogenicity of the <i>NF1</i> gene c.5606G&#x3e;T (p.Gly1869Val) variation which we defined in an affected boy who inherited the mutation from his affected father. <b><i>Conclusion:</i></b> Although <i>PTPN11</i> is the most frequently mutated gene in our patient cohort, as in most previous reports, different mutation distribution among the other genes studied motivates the use of a next-generation sequencing gene panel including the possible responsible genes.


2021 ◽  
Vol 11 ◽  
Author(s):  
Athanasia Stoupa ◽  
Ghada Al Hage Chehade ◽  
Rim Chaabane ◽  
Dulanjalee Kariyawasam ◽  
Gabor Szinnai ◽  
...  

ObjectiveTo elucidate the molecular cause in a well-characterized cohort of patients with Congenital Hypothyroidism (CH) and Dyshormonogenesis (DH) by using targeted next-generation sequencing (TNGS).Study designWe studied 19 well-characterized patients diagnosed with CH and DH by targeted NGS including genes involved in thyroid hormone production. The pathogenicity of novel mutations was assessed based on in silico prediction tool results, functional studies when possible, variant location in important protein domains, and a review of the recent literature.ResultsTNGS with variant prioritization and detailed assessment identified likely disease-causing mutations in 10 patients (53%). Monogenic defects most often involved TG, followed by DUOXA2, DUOX2, and NIS and were usually homozygous or compound heterozygous. Our review shows the importance of the detailed phenotypic description of patients and accurate analysis of variants to provide a molecular diagnosis.ConclusionsIn a clinically well-characterized cohort, TNGS had a diagnostic yield of 53%, in accordance with previous studies using a similar strategy. TG mutations were the most common genetic defect. TNGS identified gene mutations causing DH, thereby providing a rapid and cost-effective genetic diagnosis in patients with CH due to DH.


Author(s):  
Dario Dilernia ◽  
Pooneh Amin ◽  
Julie Flores ◽  
Arlene Stecenko ◽  
Eric Sorscher

Current approaches to characterize the mutational profile of CFTR are based on targeted mutation analysis (TMA) or whole gene studies derived from short-read next generation sequencing (NGS). However, these methods lack phasing capability which, in certain scenarios, can provide clinically valuable information. In the present work, we performed near-full length CFTR using Single-Molecule Real-Time Sequencing to produce haplotype resolved data from F508del homozygous and F508del compound heterozygous individuals. This approach utilizes target enrichment of the CFTR gene using biotinylated probes, facilitates multiplexing samples in the same sequencing run, and utilizes fully-automated bioinformatics pipelines for error correction and variant calling. We show a remarkable conservation of F508del haplotype, consistent with the single gene founder effect, as well as diverse mutational profiles in non-F508del alleles. By the same method, 105 single nucleotide polymorphisms exhibiting invariant linkage to F508del CFTR (which better define the founder haplotype) were identified. High level homology between F508del sequences derived from heterozygotes, and those obtained from homozygous individuals, demonstrate accuracy of this method to produce haplotype resolved sequencing. The studies provide a new diagnostic technology for detailed analysis of complex CFTR alleles linked to disease severity.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Shunqiao Feng ◽  
Lin Han ◽  
Mei Yue ◽  
Dixiao Zhong ◽  
Jing Cao ◽  
...  

Abstract Background Langerhans cell histiocytosis (LCH) is a rare neoplastic disease that occurs in both children and adults, and BRAF V600E is detected in up to 64% of the patients. Several studies have discussed the associations between BRAF V600E mutation and clinicopathological manifestations, but no clear conclusions have been drawn regarding the clinical significance of the mutation in pediatric patients. Results We retrieved the clinical information for 148 pediatric LCH patients and investigated the BRAF V600E mutation using next-generation sequencing alone or with droplet digital PCR. The overall positive rate of BRAF V600E was 60/148 (41%). The type of sample (peripheral blood and formalin-fixed paraffin-embedded tissue) used for testing was significantly associated with the BRAF V600E mutation status (p-value = 0.000 and 0.000). The risk of recurrence declined in patients who received targeted therapy (p-value = 0.006; hazard ratio 0.164, 95%CI: 0.046 to 0.583). However, no correlation was found between the BRAF V600E status and gender, age, stage, specific organ affected, TP53 mutation status, masses close to the lesion or recurrence. Conclusions This is the largest pediatric LCH study conducted with a Chinese population to date. BRAF V600E in LCH may occur less in East Asian populations than in other ethnic groups, regardless of age. Biopsy tissue is a more sensitive sample for BRAF mutation screening because not all of circulating DNA is tumoral. Approaches with low limit of detection or high sensitivity are recommended for mutation screening to avoid type I and II errors.


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