CPT® Code 81402

Molecular pathology procedure, Level 3 (eg, >10 SNPs, 2-10 methylated variants, or 2-10 somatic variants [typically using non-sequencing target variant analysis], immunoglobulin and T-cell receptor gene rearrangements, duplication/deletion variants of 1 exon, loss of heterozygosity [LOH], uniparental disomy [UPD])

Chromosome 1p-/19q- (eg, glial tumors), deletion analysis

Chromosome 18q- (eg, D18S55, D18S58, D18S61, D18S64, and D18S69) (eg, colon cancer), allelic imbalance assessment (ie, loss of heterozygosity)

COL1A1/PDGFB (t(17;22)) (eg, dermatofibrosarcoma protuberans), translocation analysis, multiple breakpoints, qualitative, and quantitative, if performed

CYP21A2 (cytochrome P450, family 21, subfamily A, polypeptide 2) (eg, congenital adrenal hyperplasia, 21-hydroxylase deficiency), common variants (eg, IVS2-13G, P30L, I172N, exon 6 mutation cluster [I235N, V236E, M238K], V281L, L307FfsX6, Q318X, R356W, P453S, G110VfsX21, 30-kb deletion variant)

ESR1/PGR (receptor 1/progesterone receptor) ratio (eg, breast cancer)

MEFV (Mediterranean fever) (eg, familial Mediterranean fever), common variants (eg, E148Q, P369S, F479L, M680I, I692del, M694V, M694I, K695R, V726A, A744S, R761H)

TRD@ (T cell antigen receptor, delta) (eg, leukemia and lymphoma), gene rearrangement analysis, evaluation to detect abnormal clonal population

Uniparental disomy (UPD) (eg, Russell-Silver syndrome, Prader-Willi/Angelman syndrome), short tandem repeat (STR) analysis

Molecular pathology procedures are specialized tests conducted at the molecular level to aid in the diagnosis, treatment, and prognostic evaluation of various genetic disorders, cancers, infectious diseases, and to assess tissue histocompatibility in transplant scenarios. These procedures are categorized by complexity, with different levels reflecting the extent of professional involvement and laboratory resources required. Specifically, Level 3 molecular pathology procedures, as denoted by CPT® Code 81402, encompass a range of tests that involve the identification of more than 10 single nucleotide polymorphisms (SNPs), 2 to 10 methylated variants, or 2 to 10 somatic variants, typically utilizing non-sequencing target variant analysis. Additionally, this level includes the analysis of immunoglobulin and T-cell receptor gene rearrangements, duplication or deletion variants of a single exon, loss of heterozygosity (LOH), and uniparental disomy (UPD). The molecular pathologist plays a critical role in this process by reviewing the patient's medical history, clinical findings, and results from other diagnostic tests before proceeding with the Level 3 test. The tests covered under this code are explicitly defined, but it is important to note that other molecular pathology procedures requiring similar levels of expertise, work, and laboratory costs, and employing comparable techniques, may also be reported using CPT® Code 81402 if they do not have a more specific code. Upon completion of the test, the molecular pathologist interprets the results and generates a comprehensive written report detailing the findings, which is essential for guiding further clinical decision-making.