CPT® Code 81175

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

The CPT® Code 81175 refers to a comprehensive gene analysis of the ASXL1 gene, which stands for additional sex combs like 1, a transcriptional regulator. This analysis is particularly relevant in the context of certain hematological conditions, including 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 conditions may exhibit symptoms such as anemia, neutropenia (a deficiency of neutrophils), and/or thrombocytopenia (a deficiency of platelets). The ASXL1 gene is located on the long (q) arm of chromosome 20 at position 11.21 and plays a crucial role in chromatin remodeling, which is the process of altering the structure of chromatin to regulate gene expression. Chromatin is a complex of DNA and proteins that packages DNA into chromosomes. The remodeling of chromatin can either condense or relax the DNA structure, thereby influencing gene expression levels. When chromatin is densely packed, gene expression is typically repressed, while loosely packed chromatin allows for increased gene expression. The gene analysis performed under this code may be utilized to differentiate the diagnosis of MDS in patients who present with cytopenia but do not show an increase in blast cells in peripheral blood samples. It can also assist in diagnosing MDS when the bone marrow sample is suboptimal or when karyotypic changes are uninformative, along with equivocal morphologic findings. The testing is conducted using next-generation sequencing (NGS) to analyze the full gene sequence, which provides a comprehensive understanding of potential mutations within the ASXL1 gene.