CPT® Code 81403

Molecular pathology procedure, Level 4 (eg, analysis of single exon by DNA sequence analysis, analysis of >10 amplicons using multiplex PCR in 2 or more independent reactions, mutation scanning or duplication/deletion variants of 2-5 exons)

ANG (angiogenin, ribonuclease, RNase A family, 5) (eg, amyotrophic lateral sclerosis), full gene sequence

ARX (aristaless related homeobox) (eg, X-linked lissencephaly with ambiguous genitalia, X-linked intellectual disability), duplication/deletion analysis

CEL (carboxyl ester lipase [bile salt-stimulated lipase]) (eg, maturity-onset diabetes of the young [MODY]), targeted sequence analysis of exon 11 (eg, c.1785delC, c.1686delT)

CTNNB1 (catenin [cadherin-associated protein], beta 1, 88kDa) (eg, desmoid tumors), targeted sequence analysis (eg, exon 3)

DAZ/SRY (deleted in azoospermia and sex determining region Y) (eg, male infertility), common deletions (eg, AZFa, AZFb, AZFc, AZFd)

DNMT3A (DNA [cytosine-5-]-methyltransferase 3 alpha) (eg, acute myeloid leukemia), targeted sequence analysis (eg, exon 23)

EPCAM (epithelial cell adhesion molecule) (eg, Lynch syndrome), duplication/deletion analysis

F8 (coagulation factor VIII) (eg, hemophilia A), inversion analysis, intron 1 and intron 22A

F12 (coagulation factor XII [Hageman factor]) (eg, angioedema, hereditary, type III; factor XII deficiency), targeted sequence analysis of exon 9

FGFR3 (fibroblast growth factor receptor 3) (eg, isolated craniosynostosis), targeted sequence analysis (eg, exon 7)

(For targeted sequence analysis of multiple FGFR3 exons, use 81404)

GJB1 (gap junction protein, beta 1) (eg, Charcot-Marie-Tooth X-linked), full gene sequence

GNAQ (guanine nucleotide-binding protein G[q] subunit alpha) (eg, uveal melanoma), common variants (eg, R183, Q209)

Human erythrocyte antigen gene analyses (eg, SLC14A1 [Kidd blood group], BCAM [Lutheran blood group], ICAM4 [Landsteiner-Wiener blood group], SLC4A1 [Diego blood group], AQP1 [Colton blood group], ERMAP [Scianna blood group], RHCE [Rh blood group, CcEe antigens], KEL [Kell blood group], DARC [Duffy blood group], GYPA, GYPB, GYPE [MNS blood group], ART4 [Dombrock blood group]) (eg, sickle-cell disease, thalassemia, hemolytic transfusion reactions, hemolytic disease of the fetus or newborn), common variants

HRAS (v-Ha-ras Harvey rat sarcoma viral oncogene homolog) (eg, Costello syndrome), exon 2 sequence

KCNC3 (potassium voltage-gated channel, Shaw-related subfamily, member 3) (eg, spinocerebellar ataxia), targeted sequence analysis (eg, exon 2)

KCNJ2 (potassium inwardly-rectifying channel, subfamily J, member 2) (eg, Andersen-Tawil syndrome), full gene sequence

KCNJ11 (potassium inwardly-rectifying channel, subfamily J, member 11) (eg, familial hyperinsulinism), full gene sequence

Killer cell immunoglobulin-like receptor (KIR) gene family (eg, hematopoietic stem cell transplantation), genotyping of KIR family genes

Known familial variant not otherwise specified, for gene listed in Tier 1 or Tier 2, or identified during a genomic sequencing procedure, DNA sequence analysis, each variant exon

(For a known familial variant that is considered a common variant, use specific common variant Tier 1 or Tier 2 code)

MC4R (melanocortin 4 receptor) (eg, obesity), full gene sequence

MICA (MHC class I polypeptide-related sequence A) (eg, solid organ transplantation), common variants (eg, *001, *002)

MT-RNR1 (mitochondrially encoded 12S RNA) (eg, nonsyndromic hearing loss), full gene sequence

MT-TS1 (mitochondrially encoded tRNA serine 1) (eg, nonsyndromic hearing loss), full gene sequence

NDP (Norrie disease [pseudoglioma]) (eg, Norrie disease), duplication/deletion analysis

NHLRC1 (NHL repeat containing 1) (eg, progressive myoclonus epilepsy), full gene sequence

PHOX2B (paired-like homeobox 2b) (eg, congenital central hypoventilation syndrome), duplication/deletion analysis

PLN (phospholamban) (eg, dilated cardiomyopathy, hypertrophic cardiomyopathy), full gene sequence

RHD (Rh blood group, D antigen) (eg, hemolytic disease of the fetus and newborn, Rh maternal/fetal compatibility), deletion analysis (eg, exons 4, 5, and 7, pseudogene)

RHD (Rh blood group, D antigen) (eg, hemolytic disease of the fetus and newborn, Rh maternal/fetal compatibility), deletion analysis (eg, exons 4, 5, and 7, pseudogene), performed on cell-free fetal DNA in maternal blood

(For human erythrocyte gene analysis of RHD, use a separate unit of 81403)

SH2D1A (SH2 domain containing 1A) (eg, X-linked lymphoproliferative syndrome), duplication/deletion analysis

TWIST1 (twist homolog 1 [Drosophila]) (eg, Saethre-Chotzen syndrome), duplication/deletion analysis

UBA1 (ubiquitin-like modifier activating enzyme 1) (eg, spinal muscular atrophy, X-linked), targeted sequence analysis (eg, exon 15)

VHL (von Hippel-Lindau tumor suppressor) (eg, von Hippel-Lindau familial cancer syndrome), deletion/duplication analysis

VWF (von Willebrand factor) (eg, von Willebrand disease types 2A, 2B, 2M), targeted sequence analysis (eg, exon 28)

Molecular pathology procedures are specialized tests conducted at the molecular level to diagnose, treat, and provide prognostic indicators for various genetic disorders, cancers, infectious diseases, and to assess tissue histocompatibility in transplant procedures. These procedures are categorized into different levels based on their complexity, which reflects the amount of professional work and laboratory costs involved in performing them. Specifically, Level 4 molecular pathology tests encompass a range of analyses, including the examination of a single exon through DNA sequence analysis, the analysis of more than ten amplicons utilizing multiplex polymerase chain reaction (PCR) across two or more independent reactions, as well as mutation scanning or the identification of duplication/deletion variants affecting two to five exons. The process begins with a thorough review of the patient's medical history, clinical findings, and results from other diagnostic tests and procedures by a molecular pathologist. Following this comprehensive evaluation, the Level 4 test is conducted. This code, CPT® 81403, encompasses a variety of specific Level 4 tests that are explicitly identified. Additionally, any molecular pathology procedures that require a similar level of professional expertise, involve comparable amounts of work and laboratory costs, and utilize similar techniques but lack a more specific code should also be reported using this code. Upon completion of the test, the molecular pathologist interprets the results and generates a detailed written report outlining the findings, which is essential for guiding further clinical decision-making.