CPT® Code 81280

Deleted

Long QT syndrome gene analyses (eg, KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2, KCNJ2, CACNA1C, CAV3, SCN4B, AKAP, SNTA1, and ANK2); full sequence analysis

Molecular genetic testing, specifically CPT® Code 81280, is utilized to identify specific gene mutations that are responsible for long QT syndrome (LQTS). LQTS is a rare, inherited cardiac condition characterized by delayed repolarization of the heart, which can lead to serious complications. This condition is particularly sensitive to adrenergic stimulation, such as during exercise or emotional excitement. The genetic mutations associated with LQTS prolong the duration of the ventricular action potential, resulting in an extended QT interval on an electrocardiogram (ECG). Individuals diagnosed with LQTS face an increased risk of developing irregular heart rhythms, experiencing cardiac palpitations, having syncopal episodes (fainting), and potentially suffering sudden cardiac death due to ventricular fibrillation. The mutations that cause LQTS can be inherited in an autosomal dominant or recessive manner. The more severe recessive phenotypes may also be associated with additional physical anomalies, such as syndactyly (fused fingers or toes) and congenital neural deafness. The full sequence analysis performed under CPT® Code 81280 involves a comprehensive examination of gene segments to identify similarities or differences, thereby elucidating relationships among them. This analysis includes studying intrinsic features to locate active sites for post-translational modifications, as well as understanding the gene structures and the distribution of introns, exons, and regulatory elements. Genetic markers are identified through the detection of point mutations or single nucleotide polymorphisms (SNPs). Notably, the most prevalent mutation associated with LQTS, known as LQT1, is located on the KCNQ1 gene on chromosome 11 and is found in approximately 30-35% of individuals diagnosed with this syndrome.