CurrentCapital BluecrossPolicy MP 2.355

Genetic Testing for the Diagnosis of Inherited Peripheral Neuropathies

This policy governs when genetic testing is considered medically necessary for diagnosing suspected inherited peripheral motor or sensory neuropathies for members covered by applicable Capital BlueCross products.

Policy Summary

PayerCapital Bluecross

PolicyGenetic Testing for the Diagnosis of Inherited Peripheral Neuropathies

Policy CodePolicy MP 2.355

Change TypeNo material changes

Effective DateMay 1, 2025

Next Review DateN/A

Key ActionObtain clinical evaluation including nerve conduction studies and document a three-generation family history; order genetic testing in the context of genetic counseling when diagnosis cannot be confirmed clinically.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

1 in 2500estimated prevalence

>30genes implicated

70-80%CMT1A proportion

No disease-modifying therapytherapeutic status

Trek Health ingests and normalizes Transparency in Coverage data and payer policy updates to give provider organizations a clear view of how commercial reimbursement behaves across markets, payers, and services. Our platform transforms raw payer disclosures into structured intelligence that supports contract evaluation, payer negotiations, and service line strategy. By combining market benchmarks with ongoing policy visibility, Trek helps teams identify variability, risk, and opportunity in commercial reimbursement. The result is faster insight, stronger negotiating positions, and more informed financial decisions.

policy history entries

Coverage Criteria

inv-01: Medically necessary indication

Covered when ALL of the following are met:

Primary coverage condition: Genetic testing is considered medically necessary when the diagnosis of an inherited peripheral motor or sensory neuropathy is suspected due to signs and/or symptoms, but a definitive diagnosis cannot be made without genetic testing.

From policy statement (MP 2.355)

inv-02: Diagnostic genetic testing for inherited peripheral neuropathy

Covered when testing is medically necessary to establish diagnosis of suspected inherited peripheral neuropathy and when results will inform management

General coverage logic: Testing is supported for diagnosis of suspected inherited motor or sensory peripheral neuropathy when clinical evaluation (including nerve conduction studies and family history) suggests a genetic etiology and a definitive diagnosis cannot be made by other methods.

Evidence supports diagnostic yield, particularly with sequential, phenotype-directed testing; testing methods include single-gene sequencing, multi-gene NGS panels, and deletion/duplication analysis performed in clinical laboratories.

Genetic testing for an inherited peripheral neuropathy is investigational when performed for indications other than establishing the diagnosis of a suspected inherited peripheral motor or sensory neuropathy. The policy states that there is insufficient evidence to support general health outcome benefits of testing for other uses, and testing outside the diagnostic context may be denied as investigational.

The existence of this medical policy does not guarantee that a particular genetic test or related service is a covered benefit for a given member. Coverage and benefit determinations are based on the member's applicable health benefit plan language; members and providers should consult the member's plan or contact Capital Blue Cross for benefit information.

Within the document excerpts reviewed, there are no explicit test-specific exclusions listed; the policy history and coding sections were updated over time, but the provided chunks do not enumerate any explicit exclusions of particular tests or technologies.

Genetic testing for inherited peripheral neuropathy is considered investigational when used for indications other than diagnosing a suspected inherited peripheral motor or sensory neuropathy. The policy specifies that testing is medically indicated only when a definitive diagnosis cannot be made without genetic testing.

Although direct trials demonstrating improved clinical outcomes from genetic testing are lacking, the policy notes that a chain of evidence supports the diagnostic utility of genetic testing to establish a molecular diagnosis when clinical evaluation cannot provide one. Diagnostic yield is reported to be higher when testing is tailored by phenotype and when sequential testing strategies are used, supporting clinical utility for diagnosis and subsequent management decisions despite limited direct outcome trials.

No explicit statements labeling services as not medically necessary are present in the provided document chunks; the policy instead distinguishes investigational uses (outside diagnostic indications) and documents its review history without adding explicit NMN language in these excerpts.

Covered Indications

inv-32: Diagnosis of an inherited peripheral motor or sensory neuropathy when clinical features, family history, and ancillary testing suggest a genetic etiology but definitive diagnosis requires genetic testing.

Clinical and ancillary findings: Clinical features consistent with an inherited peripheral motor or sensory neuropathy (e.g., generalized polyneuropathy, early onset, symmetry, very slowly progressive course, distal weakness or sensory loss) AND supportive ancillary testing findings (e.g., nerve conduction studies suggestive of demyelinating or axonal neuropathy).

Family history across at least 3 generations should be collected.

Family history suggestive of inherited neuropathy (preferably documented across at least 3 generations with health issues, ages, and causes of death).

Inheritance patterns (AD, AR, X-linked) inform testing choice; collect detailed three-generation pedigree.

Diagnostic necessity: A definitive diagnosis cannot be established by clinical assessment and ancillary testing alone and genetic testing is expected to clarify diagnosis or guide management/supportive care.

Coding

Note

Coding information

Note: This list of codes may not be all-inclusive, and codes are subject to change. Identification of a code does not guarantee coverage; coverage is determined by member benefits. Not all covered services are eligible for separate reimbursement.

Covered CPT / Procedure CodesCPTCovered

81325	Molecular pathology procedure (specific gene testing)
81326	Molecular pathology procedure (additional genes)
81403	Molecular pathology procedure; tier 1 panel
81404	Molecular pathology procedure; tier 2 panel
81405	Molecular pathology procedure; tier 3 panel
81406	Molecular pathology procedure; tier 4 panel
81448	Targeted gene panel analysis
81479	Unlisted molecular pathology procedure

Relevant ICD-10 Diagnosis CodesICD-10

G60.0	Hereditary motor and sensory neuropathy
G60.8	Other hereditary and idiopathic neuropathies
G60.9	Hereditary and idiopathic neuropathy, unspecified
Z31.430	Encounter for testing for genetic disease carrier status, female
Z31.440	Encounter for testing for genetic disease carrier status, male

Documentation Required

Provider action / documentation

Providers must ensure documentation of: 1) clinical indication and relevant signs/symptoms; 2) that genetic counseling was offered or provided and informed consent obtained; and 3) test type and genes analyzed. Failure to document these elements may result in denial.

Affected codes: 81325, 81326, 81403–81406, 81448, 81479
Genetic counseling recommended prior to testing; document counseling in the record

Provider Actions and Requirements

Note

Product and program applicability

This policy applies only to certain Capital BlueCross programs and products and is subject to benefit variations; FEP members should follow the FEP Medical Policy Manual referenced in the policy.

Policy applicability is limited to certain Capital BlueCross programs and products.
FEP PPO members: refer to the FEP Medical Policy Manual at the FEP website.

Prior Authorization

Prior authorization

No explicit prior authorization requirement is stated in the provided policy excerpts; providers should verify the member's benefit plan for any plan-specific prior authorization rules.

The coding section notes code identification does not denote coverage; coverage is determined by member benefit information.
Benefit-specific prior authorization requirements are not specified in these chunks.

Eligibility Requirements

Obtain a detailed family history that spans at least 3 generations, including affected and unaffected relatives, major health issues, causes and ages at death, and relevant neurologic findings. This pedigree information supports assessment of inheritance patterns and is recommended to justify genetic testing for suspected inherited peripheral neuropathies.

No top-level eligibility requirement nodes were identified in the provided excerpt for this placeholder entry.

Not Covered / Investigational

Genetic testing for inherited peripheral neuropathy is considered investigational and not covered for any indication other than diagnosis of a suspected inherited peripheral motor or sensory neuropathy. The policy states that there is insufficient evidence to support testing for other indications.

The document does not list explicit exclusions of particular tests; it notes that direct evidence for improved clinical outcomes is limited, and clinical utility in terms of outcome improvement is unknown in direct trials, although diagnostic use is supported by a chain of evidence.

In the provided chunks there are no explicitly excluded tests or indications identified; coding and policy history were reviewed and updated but did not introduce specific exclusions in these excerpts.

Definitions

Variant classification (ACMG-AMP)

Recommended terminologyPathogenic; Likely pathogenic; Variant of uncertain significance (VUS); Likely benign; Benign

Source guidanceACMG-AMP standards and guidelines for interpretation of sequence variants

Reporting nomenclatureHuman Genome Variation Society (HGVS) nomenclature recommended for variant descriptions

CMT1 vs CMT2 — key distinctions

Primary distinctionCMT1 is demyelinating (slow nerve conduction velocities); CMT2 is axonal (normal or near-normal conduction velocities)

Inheritance patternsCMT1 is typically autosomal dominant; CMT2 subtypes are mostly autosomal dominant with some autosomal recessive subtypes

Background

Inherited peripheral neuropathies are a clinically and genetically heterogeneous group with an estimated prevalence of approximately 1 in 2,500. They may be inherited in autosomal dominant, autosomal recessive, or X-linked manners and are commonly subdivided into demyelinating (e.g., CMT1) and axonal (e.g., CMT2) forms. Clinical features that raise suspicion for an inherited neuropathy include distal symmetric weakness, sensory loss, early onset, slowly progressive course, and supportive findings on nerve conduction studies; genetic testing is used when a definitive diagnosis cannot be made by clinical evaluation and electrodiagnostic testing alone.

Revision History

2025-01-14consensus reviewLatest

Consensus review completed; no changes to the policy statement and coding reviewed with no changes.

2024-04-26consensus review

Consensus review completed; no change to policy statement, references updated, coding reviewed with no changes.

2023-02-09consensus review

Consensus review completed; no change to policy statement, policy guidelines and background updated, references added.

Policy Summary

PayerCapital Bluecross

PolicyGenetic Testing for the Diagnosis of Inherited Peripheral Neuropathies

Policy CodePolicy MP 2.355

Change TypeNo material changes

Effective DateMay 1, 2025

Next Review DateN/A

SourceLink

On This Page

Per policy, genetic testing is medically necessary only when needed to make a definitive diagnosis.

inv-33: Suspected inherited motor and sensory peripheral neuropathy (including CMT subtypes and HNPP) where genetic testing will aid diagnosis and management; testing yield higher when tailored/ sequential.

Testing approach: Genetic testing approaches may include single-gene testing, targeted multi-gene next-generation sequencing panels, and deletion/duplication analysis (copy number analysis); choose testing strategy tailored to the patient phenotype and inheritance pattern.

Sequential/phenotype-directed testing can increase diagnostic yield.

When to prefer single-gene testing: Single-gene testing (including targeted sequencing and deletion/duplication analysis) is appropriate when clinical and electrophysiologic features and family history strongly point to a specific gene (e.g., PMP22 duplication/deletion for CMT1A/HNPP, GJB1 for CMTX1, MFN2 for CMT2A).

PMP22 testing for duplication/deletion has high yield in CMT1/CMT1A; GJB1 testing detects ~90% of CMTX1 cases.

When to prefer multi-gene panel testing: Use of targeted multi-gene panels that include sequence analysis plus copy number analysis is appropriate when phenotype is less specific or multiple genes could explain the presentation; panels provide higher overall diagnostic yield in many cohorts.

Commercial panels (e.g., GeneDx Axonal CMT panel, 42- and 48-gene panels) are referenced in the literature.

Laboratory standards: Testing should be performed in clinical laboratories that meet applicable regulatory standards (e.g., CLIA high-complexity) and use accepted variant classification/reporting standards (e.g., ACMG-AMP, HGVS nomenclature).

From molecular testing and laboratory guidance in policy.

inv-34: Diagnosis of inherited peripheral neuropathies such as Charcot-Marie-Tooth disease and HNPP — supported by diagnostic algorithms and panel literature.

Supported indications: Genetic testing is indicated for the diagnosis of inherited peripheral neuropathies such as Charcot–Marie–Tooth disease and hereditary neuropathy with liability to pressure palsies (HNPP) when clinical and diagnostic evaluation suggest these conditions.

Diagnostic algorithms and multiple studies and reviews support panel-based testing and combined sequence plus copy number analysis for CMT and HNPP (see cited literature).

Evidence summary: The literature demonstrates high diagnostic yield for targeted multi-gene panel testing and for sequential phenotype-directed strategies; while direct evidence of improved clinical outcomes is limited, a chain of evidence supports diagnostic use to establish etiology and guide supportive management.

References include Saporta et al., Antoniadi et al., Volodarsky et al., and others cited in policy.

Recommended testing modalities: Sequence analysis (Sanger or NGS) plus deletion/duplication (copy number) analysis on panels or targeted genes as clinically indicated.

Policy references commercial panels and methods (NGS plus exon arrays/array CGH) used by laboratories such as GeneDx, InterGenetics, and Fulgent.

Step Therapy

Clinical evaluation prior to testing

Obtain a clinical evaluation, including nerve conduction studies and a comprehensive family history, before ordering genetic testing since many diagnoses can be suggested clinically.

Clinical evaluation and nerve conduction studies often support diagnosis without genetic testing.
Collect family history across at least 3 generations with details on health issues, cause of death, and age at death.

Step Therapy

Sequential (stepwise) testing recommended

Use sequential, phenotype-directed testing (e.g., targeted gene testing followed by panels or deletion/duplication analysis) as diagnostic yield is higher when testing is tailored and performed sequentially.

Sequential testing based on patient phenotype yields higher diagnostic rates.
Testing modalities include single-gene sequencing, multi-gene NGS panels, and deletion/duplication analysis.

Step Therapy

Step therapy requirements

No step therapy requirements are specified in the policy excerpts; clinicians may use stepwise strategies but no mandatory step-therapy gates are defined.

The summary states sequential testing is beneficial but does not mandate specific prior steps.
Policy excerpts do not define required step-therapy protocols.

Documentation Required

Family history documentation

Document a family history spanning at least three generations with details on health issues, cause of death, and age at death to support a suspected genetic etiology.

Collect family history across ≥3 generations with health issues, cause of death, and age at death.

Documentation Required

Genetic counseling recommended

Recommend formal genetic counseling performed by an individual experienced in genetic medicine and testing methods when genetic testing for an inherited condition is considered; counseling should address benefits, harms, and family implications.

Genetic counseling is recommended in most cases when testing is considered.
Counseling should be by someone with expertise in genetic medicine and testing methods.

Documentation Required

Laboratory certification and documentation

Ensure testing is performed in clinical laboratories that meet CLIA requirements; laboratory-developed tests must be performed in CLIA-licensed high-complexity laboratories and documentation of such certification should be maintained.

Laboratory-developed tests must meet CLIA general regulatory standards.
Laboratories offering LDTs must be licensed by CLIA for high-complexity testing.

Note

References and diagnostic algorithms

Use the policy’s cited references and diagnostic algorithm literature (e.g., GeneDx panels, diagnostic algorithms cited in the references) as supportive resources when documenting testing rationale.

References include studies demonstrating utility of targeted multi-gene panels and diagnostic algorithms.
Cited resources may support the selection of panel content and testing approach.

Denial Risk

Investigational indications — potential denial risk

Genetic testing performed for indications other than diagnosing a suspected inherited peripheral motor or sensory neuropathy is considered investigational and may be denied.

Testing is investigational (not covered) for indications beyond suspected inherited peripheral neuropathy.

Denial Risk

Benefit determination — verify member coverage

Coverage and payment for genetic testing depend on the member’s specific health benefit plan language; the existence of this medical policy does not guarantee the service is a covered benefit.

Members and providers should consult the member’s health benefit plan or contact Capital Blue Cross for benefit information.
Medical policy does not constitute a description of benefits.

Denial Risk

Denial triggers — none specified

No explicit denial triggers are listed in the provided excerpts; providers should document clinical rationale and confirm benefit applicability to reduce risk of denial.

Policy history and coding notes do not specify discrete denial triggers in these chunks.
Documentation of medical necessity and benefit verification is advised.

Documentation Required

Document genetic counseling

Formal genetic counseling is recommended in most cases when testing is considered and counseling should be documented in the medical record.

Counseling should cover interpretation, risks/benefits, and family implications.
Document that counseling was provided and by whom.

Note

Verify benefits and document medical necessity

Providers and members should consult member benefit information prior to ordering testing; treating providers are responsible for clinical decision-making and should ensure medical necessity is documented.

Check member benefit plans for coverage details and prior authorization rules.
Treating providers are responsible for medical advice and documentation of necessity.

Note

Order testing within clinical/genetic counseling context

Order genetic testing in the context of genetic counseling and typically by clinicians managing the condition (e.g., neurologists or providers experienced with inherited neuropathies) to ensure appropriate test selection and interpretation.

Testing should be ordered in the context of genetic counseling.
Clinicians managing the condition should guide test selection and follow-up.

Note

Authorized ordering provider — no specific mandate

The policy excerpts do not mandate a specific provider type to order testing; however, providers must verify benefits and document medical necessity when ordering.

No specific provider type is required per the provided excerpts.
Emphasize benefit verification and documentation responsibilities of ordering provider.

Clinical overlapBoth present with distal muscle weakness and sensory loss but CMT1 often has more prominent slowing on nerve conduction studies

CMT1

DefinitionAutosomal dominant, demyelinating peripheral neuropathy characterized by distal muscle weakness and atrophy, sensory loss, and slow nerve conduction velocity

Typical featuresSlowly progressive; pes cavus foot deformity, bilateral foot drop, palpably enlarged peripheral nerves

Epidemiology/geneticsCMT1A (PMP22 duplication) accounts for ~70–80% of CMT1; ~2/3 inherited, ~1/3 de novo

CMT2

DefinitionAxonal (non-demyelinating) peripheral neuropathy characterized by distal muscle weakness and atrophy with mild sensory loss and normal or near-normal nerve conduction velocities

Clinical severityClinically similar to CMT1 but typically less severe

MFN2-associated proportionCMT2A (MFN2 variants) accounts for approximately 20% of CMT2 cases

HNPP

DefinitionHereditary neuropathy with liability to pressure palsies (HNPP) caused by inadequate PMP22 production leading to recurrent focal pressure neuropathies

Genetic lesionLarge PMP22 deletion in ~80% of patients; remaining ~20% have PMP22 SNVs or small deletions

Clinical featuresRecurrent focal compression neuropathies (e.g., carpal tunnel, peroneal palsy) with variable penetrance and often benign course

CMTX1 (GJB1)

DefinitionX-linked form of CMT (CMTX1) with moderate-to-severe neuropathy in males and milder/no symptoms in carrier females

Genetic testing detection rateClinical molecular testing of GJB1 (Cx32) detects about 90% of CMTX1 cases

Inheritance noteX-linked inheritance; consider sex-specific phenotypic differences when interpreting results

CMT / HNPP — general definition

General definitionCharcot–Marie–Tooth (CMT) diseases and HNPP are inherited peripheral neuropathies encompassing multiple genetic subtypes that cause distal motor and sensory dysfunction

Diagnostic approachMolecular diagnosis commonly uses targeted multi-gene panels and copy-number analysis (sequence + deletion/duplication testing)

Clinical indicatorsConsider genetic testing when clinical features, family history, and nerve conduction studies suggest a genetic etiology

2022-02-22consensus review

Consensus review completed; policy statement unchanged, references updated and coding reviewed.

2021-02-02consensus review

Consensus review completed; policy statement unchanged, references updated and coding reviewed.

2020-03-23consensus review

Consensus review completed; policy statement unchanged, references, policy guidelines, and coding updated; background reviewed.