Genetic testing identified heterozygous pathogenic variants in the KCNH2 gene in two female patients with recurrent syncope, leading to a diagnosis of congenital long QT syndrome and successful treatment with ICD implantation.
Case Report (n=2)
No
Genetic testing successfully identified KCNH2 gene mutations in two patients with congenital long QT syndrome presenting with syncope, highlighting its role in diagnosis and personalized treatment.
This study presents two cases of congenital long QT syndrome caused by KCNH2 gene mutations. It highlights the critical role of genetic testing in its diagnosis and underscores the importance of early detection and personalized treatment strategies to enhance patient outcomes. Comprehensive clinical data were collected from the patients, including measurements of the QT interval and calculations of the corrected QT interval (QTc) using the Bazett correction formula. Genetic testing identified heterozygous pathogenic variants in the KCNH2 gene in both patients. The variant in Case 1 was a frameshift mutation (c. 234₂41dup, p. Gln81Leufs*38), located in exon 2 (NM₀00238. 4). Case 2 carried a missense mutation (c. 1841C > T, p. Ala614Val) in exon 7 (NM₀00238. 4). Predictions from multiple bioinformatics tools were consistent with the pathogenicity of both variants. The findings underscore that early diagnosis and tailored therapeutic approaches are essential for improving the prognosis of individuals with long QT syndrome. It is imperative for clinicians to increase awareness of long QT syndrome, particularly in patients presenting with syncope as an initial symptom, to inform clinical diagnosis, treatment, and prognostic assessment.
Xing et al. (Wed,) conducted a case report in Congenital long QT syndrome (n=2). Genetic testing and ICD implantation was evaluated. Genetic testing identified heterozygous pathogenic variants in the KCNH2 gene in two female patients with recurrent syncope, leading to a diagnosis of congenital long QT syndrome and successful treatment with ICD implantation.