CPT® Code 81176

ASXL1 (additional sex combs like 1, transcriptional regulator) (eg, myelodysplastic syndrome, myeloproliferative neoplasms, chronic myelomonocytic leukemia), gene analysis; targeted sequence analysis (eg, exon 12)

The CPT® Code 81176 refers to the gene analysis of the ASXL1 (additional sex combs like 1) gene, which is a transcriptional regulator. This analysis is particularly relevant for conditions such as myelodysplastic syndrome (MDS), myeloproliferative neoplasms, and chronic myelomonocytic leukemia (CML). Myeloproliferative disorders are characterized by the abnormal proliferation of blood cells originating from clonal stem cells in the bone marrow. Patients with these disorders may exhibit symptoms such as anemia, neutropenia (a decrease in neutrophils), and/or thrombocytopenia (a decrease in platelets). The gene analysis performed under this code is crucial for the differential diagnosis of MDS, especially in cases where patients present with cytopenia but do not show an increase in blast cells in peripheral blood samples. It is also useful in diagnosing MDS when the bone marrow sample is suboptimal or when karyotypic changes are uninformative, along with equivocal morphologic findings. The ASXL1 gene is located on the long (q) arm of chromosome 20 at position 11.21 and encodes a protein that plays a significant role in chromatin remodeling. Chromatin is the complex of DNA and proteins that forms chromosomes, and its remodeling can influence gene expression. When chromatin is densely packed, gene expression is repressed, whereas loosely packed chromatin allows for increased gene expression. The analysis involves obtaining a sample of peripheral blood or bone marrow, which is performed as a separate procedure. The testing utilizes next-generation sequencing (NGS) to analyze the full gene or targeted sequencing specifically for exon 12.