CPT 81324, 81325, 81326, 81448 - Genetic testing

Coding  Code Description CPT

81324 PMP22 (peripheral myelin protein 22) (eg, Charcot-Marie-Tooth, hereditary neuropathy with liability to pressure palsies) gene analysis; duplication/deletion analysis

81325 PMP22 (peripheral myelin protein 22) (eg, Charcot-Marie-Tooth, hereditary neuropathy with liability to pressure palsies) gene analysis; full sequence analysis

81326 PMP22 (peripheral myelin protein 22) (eg, Charcot-Marie-Tooth, hereditary neuropathy with liability to pressure palsies) gene analysis; known familial variant

81448 Hereditary peripheral neuropathies (eg, Charcot-Marie-Tooth, spastic paraplegia), genomic sequence analysis panel, must include sequencing of at least 5 peripheral neuropathy-related genes (eg, BSCL2, GJB1, MFN2, MPZ, REEP1, SPAST, SPG11, SPTLC1) (new code effective 1/1/18)


Introduction

Neuropathy is a term related to disease or damage to nerves. Peripheral neuropathy refers to nerve disorders that affect the nerves leaving the spinal cord and going out to the body, often those nerves in the arms and legs. These neuropathies may be due to damage to nerves related to certain other conditions such as diabetes, or inflammatory or immune problems. Rarely a peripheral nerve problem is inherited and occurs in families. In these conditions genetic changes can be passed from parent to child. The most common inherited peripheral neuropathy is Charcot-Marie-Tooth (CMT) syndrome. There are different forms of CMT that result in weakness and muscles wasting away. CMT usually affects muscles in the foot, lower leg, hand, and forearm. Another type of inherited peripheral neuropathy is hereditary neuropathy with liability to pressure palsies (HNPP). In HNPP people experience numbness or tingling when there’s pressure on, or injury to a nerve. This sensation can last for a few minutes to days or months. CMT and HNPP are both uncommon and can usually be diagnosed with a physical exam. This policy discusses when genetic testing for inherited peripheral neuropathies may be medically necessary.

Policy Coverage Criteria 

Testing Medical Necessity

Genetic testing

Genetic testing for suspected but undiagnosed Charcot-Marie- Tooth (CMT) Syndrome may be considered medically necessary in the following setting: * Weakness on exam of foot, leg or hand and/or deformities or decreased ability to walk or manipulate items with hands AND * Electromyogram (EMG) and/or nerve conduction tests (NCT) are non-diagnostic  Genetic testing for suspected but undiagnosed hereditary neuropathy with liability to pressure palsies (HNPP) may be considered medically necessary in the following setting: * Person with transient compression neuropathy which may include pain, numbness or weakness  AND * EMG and/or NCT have been non-diagnostic Testing Investigational

Genetic testing Genetic testing for an inherited peripheral or sensory neuropathy is considered investigational for all other indications not outlined above.



Related Information 
 
This policy addresses the hereditary motor and sensory peripheral neuropathies, of which peripheral neuropathy is the primary clinical manifestation. A number of other hereditary disorders may have neuropathy as an associated finding but typically have other central nervous system and occasionally other systemic findings. Examples include Refsum disease, various lysosomal storage diseases, and mitochondrial disorders.

Definition of Terms

Charcot-Marie-Tooth (CMT) neuropathy: This inherited disease is a group of progressive disorders that affect the peripheral nerves. Peripheral nerves connect the brain and spinal cord to muscles and to sensory cells that detect touch, pain, heat and sound. Damage to the peripheral nerves can result in loss of sensation and wasting (atrophy) of muscles in the arms and legs. This is also known as peroneal muscular atrophy, or progressive neural muscular atrophy or hereditary motor and sensory neuropathy.

Hereditary neuropathy with liability to pressure palsies (HNPP): This is a slowly progressive disorder affecting peripheral nerves. It is caused by deletions of the PMP22 gene that instructs the body to make a protein (ie, peripheral myelin protein 22) that plays a crucial role in the production and maintenance of myelin in the peripheral nervous system. HNPP increases the probability of nerve injury from stretch, pressure or repetitive use. The injured nerves lose their insulating covering; added pressure causes pain, numbness, weakness or even paralysis in the area. The disorder may sometimes be diagnosed during a work-up for carpal tunnel syndrome or peroneal palsy.

Genetic Counseling

Genetic counseling is primarily aimed at patients who are at risk for inherited disorders, and experts recommend formal genetic counseling in most cases when genetic testing for an inherited condition is considered. The interpretation of the results of genetic tests and the understanding of risk factors can be very difficult and complex. Therefore, genetic counseling will assist individuals in understanding the possible benefits and harms of genetic testing, including the possible impact of the information on the individual’s family. Genetic counseling may alter the utilization of genetic testing substantially and may reduce inappropriate testing. Genetic counseling should be performed by an individual with experience and expertise in genetic medicine and genetic testing methods.