PURPOSE: This study aimed to identify potential epidermal growth factor receptor (EGFR) gene mutations in non-small cell lung cancer that went undetected by amplification refractory mutation system-Scorpion real-time PCR (ARMS-PCR). MATERIALS AND METHODS: A total of 200 specimens were obtained from the First Affiliated Hospital of Guangzhou Medical University from August 2014 to August 2015. In total, 100 ARMS-negative and 100 ARMS-positive specimens were evaluated for EGFR gene mutations by Sanger sequencing. The methodology and sensitivity of each method and the outcomes of EGFR-tyrosine kinase inhibitor (TKI) therapy were analyzed. RESULTS: Among the 100 ARMS-PCR-positive samples, 90 were positive by Sanger sequencing, while 10 cases were considered negative, because the mutation abundance was less than 10%. Among the 100 negative cases, three were positive for a rare EGFR mutation by Sanger sequencing. In the curative effect analysis of EGFR-TKIs, the progression-free survival (PFS) analysis based on ARMS and Sanger sequencing results showed no difference. However, the PFS of patients with a high abundance of EGFR mutation was 12.4 months [95% confidence interval (CI), 11.6−12.4 months], which was significantly higher than that of patients with a low abundance of mutations detected by Sanger sequencing (95% CI, 10.7−11.3 months) (p < 0.001). CONCLUSION: The ARMS method demonstrated higher sensitivity than Sanger sequencing, but was prone to missing mutations due to primer design. Sanger sequencing was able to detect rare EGFR mutations and deemed applicable for confirming EGFR status. A clinical trial evaluating the efficacy of EGFR-TKIs in patients with rare EGFR mutations is needed.
Adenocarcinoma/genetics ; Adenocarcinoma/pathology ; Aged ; Aged, 80 and over ; Animals ; Base Sequence ; Disease-Free Survival ; Female ; Humans ; Lung Neoplasms/genetics ; Lung Neoplasms/pathology ; Male ; Middle Aged ; Mutation/genetics ; Mutation Rate ; Real-Time Polymerase Chain Reaction/methods ; Receptor, Epidermal Growth Factor/genetics ; Sequence Analysis, DNA/methods ; Treatment Outcome

INTRODUCTIONRetinitis pigmentosa (RP) is the most prevalent group of inherited retinopathies and demonstrates considerable clinical and genetic heterogeneity, with wide variations in disease severity, progression, and gene involvement. We studied a large family with RP to determine the pattern of inheritance and to identify the disease-causing gene/locus.

MATERIALS AND METHODSOphthalmic examination was performed on 35 family members to identify affected individuals and carriers and to characterise the disease phenotype. Genetic linkage analysis was performed using short tandem repeat (STR) polymorphic markers encompassing the known loci for Xlinked RP (xlRP) including RP2, RP3, RP6, RP23, and RP24. Mutation screening was performed by direct sequencing of PCR-amplified genomic DNA of the RP2 and RPGR genes of the affected individuals.

RESULTSA highly penetrant, X-linked form of RP was observed in this family. Age of onset was from 5 to 8 years and visual acuity ranged from 20/25 in children to light perception in older adults. Linkage analysis and direct sequencing showed that no known loci/genes were associated with the phenotype in this kindred.

CONCLUSIONA novel disease gene locus/loci is responsible for the xlRP phenotype in this family.

Adolescent ; Adult ; Age of Onset ; Child ; Child, Preschool ; Chromosome Mapping ; DNA Mutational Analysis ; Eye Proteins ; genetics ; Female ; Genetic Diseases, X-Linked ; genetics ; Humans ; Intracellular Signaling Peptides and Proteins ; genetics ; Lod Score ; Male ; Membrane Proteins ; genetics ; Pedigree ; Phenotype ; Retinitis Pigmentosa ; genetics