||Mitochondrial DNA Deletion Syndromes
||November 13, 2017
||November 13, 2017
Mitochondrial DNA deletion syndromes include three overlapping phenotypes: Kearns-Sayre syndrome (KSS), Pearson syndrome, and progressive external ophthalmoplegia (PEO). These three phenotypes may be observed in different members of the same family or may evolve in a given individual over time.
KSS is a multisystem disorder defined by three key signs and symptoms: onset before age 20 years (typically in childhood), pigmentary retinopathy, and PEO. Affected individuals must also have at least one of the following: cardiac conduction block, cerebrospinal fluid protein concentration >100 mg/dL, or cerebellar ataxia. Other findings may include short stature, hearing loss, dementia, limb weakness, diabetes mellitus, hypoparathyroidism, and growth hormone deficiency.
Pearson syndrome includes the findings of sideroblastic anemia and exocrine pancreas dysfunction. It is usually fatal in infancy. Those surviving into childhood develop features of KSS. Symptoms may first occur between the first and fifth decade of life and may not appear in any particular order.
PEO is a mitochondrial myopathy characterized by findings including drooping of the eyelids (ptosis), paralysis of the extraocular muscles (ophthalmoplegia), and variably severe proximal limb weakness. Rarely Leigh syndrome can manifest due to a mtDNA deletion which is characterized by basal ganglia and brain stem lesions.
These conditions are caused by pathogenic variants in mitochondrial DNA (mtDNA). Pathogenic variants can be sporadic (not inherited) or maternally inherited. A female who carries the mtDNA mutation at high mutation load will typically pass it on to all of her children. A male who carries the mtDNA mutation cannot pass it on to his children.
This policy is designed to address medical guidelines that are appropriate for the majority of individuals with a particular disease, illness, or condition. Each person's unique clinical circumstances may warrant individual consideration, based on review of applicable medical records.
|Policy Position Coverage is subject to the specific terms of the member’s benefit plan.|
Known familial mutation testing may be considered medically necessary when the following criteria have been met:
- Genetic Counseling:
- Pre and post-test counseling by an appropriate provider; and
- Previous Genetic Testing:
- No previous genetic testing in the individual for mtDNA deletion syndromes; and
- A maternal deletion identified in the mother; and
- Diagnostic Testing for Symptomatic Individual:
- Clinical exam and/or biochemical testing suggestive, but not confirmatory, of a diagnosis of a mtDNA deletion syndrome.
mtDNA deletion testing may be considered medically necessary when the following criteria have been met:
- Genetic Counseling:
- Pre and post-test counseling by an appropriate provider; and
- Previous Testing: o No previous genetic testing for mtDNA deletions*; and
- No known mitochondrial pathogenic variants or deletions in the family; and
- Diagnostic Testing for Symptomatic Individuals:
- Clinical exam and/or biochemical testing suggestive, but not confirmatory, of a diagnosis of a mtDNA deletion syndrome; and
- Genetic testing is needed to confirm the diagnosis.
*Exceptions may be considered if technical advances in testing demonstrate significant advantages that would support a medical need to retest.
|Professional Statements and Societal Positions|
Guidelines and Evidence
- No specific evidence-based U.S. testing guidelines were identified.
- Case reports and a limited number of case series is the primary evidence base available for the diagnosis of mitochondrial disease. There are few prospective studies. The Mitochondrial Medicine Society developed consensus recommendations using the Delphi method and published them in 2015.
- Recommendations for DNA testing;
- “Massively parallel sequencing/NGS of the mtDNA genome is the preferred methodology when testing mtDNA and should be performed in cases of suspected mitochondrial disease instead of testing for a limited number of pathogenic point mutations.”
- “Patients with a strong likelihood of mitochondrial disease because of a mtDNA mutation and negative testing in blood, should have mtDNA assessed in another tissue to avoid the possibility of missing tissue-specific mutations or low levels of heteroplasmy in blood; tissue-based testing also helps assess the risk of other organ involvement and heterogeneity in family members and to guide genetic counseling.”
- “Heteroplasmy analysis in urine can selectively be more informative and accurate than testing in blood alone, especially in cases of MELAS due to the common m.3243 A>G mutation.”
- “When considering nuclear gene testing in patients with likely primary mitochondrial disease, NGS methodologies providing complete coverage of known mitochondrial disease gene is preferred. Single-gene testing should usually be avoided because mutations in different genes can produce the same phenotype. If no mutation is identified via known NGS panels, then whole exome sequencing should be considered.”
- A workshop of the National Institute of Neurological Disorders and Stroke (2008) summarizes:
- "The diagnosis of mitochondrial diseases is complicated by their heterogeneous presentations and by the lack of screening procedures or diagnostic biomarkers that are both sensitive and specific. The workshop panelists explained that diagnosis is often a lengthy process beginning with a general clinical evaluation followed by metabolic screening and imaging and finally by genetic tests and more invasive biochemical and histological analyses. The identification of known mitochondrial mutations in tissue has greatly aided diagnosis. However, even when clinical features and family history strongly suggest mitochondrial disease, the underlying genetic mutation can elude detection, and there is no current screening procedure that would be practical for all cases of suspected mitochondrial disease."
- The European Federation of Neurological Sciences (2009) provided molecular diagnostic evidence-based guidelines for these conditions:
- "If the phenotype suggests syndromic MID [mitochondrial disorders] due to mtDNA deletion (mtPEO, KSS, Pearson's syndrome), mtDNA analysis starts with RFLP or Southern-blot from appropriate tissues. mtDNA deletions with low heteroplasmy rate may be detected only by long-range PCR. If neither a single deletion nor multiple deletions are found, mtDNA sequencing is recommended."
|Place of Service: Outpatient|
Mitochondrial DNA deletion syndromes are typically an outpatient procedure which is only eligible for coverage as an inpatient procedure in special circumstances, including, but not limited to, the presence of a co-morbid condition that would require monitoring in a more controlled environment such as the inpatient setting.
|The policy position applies to all commercial lines of business|
Services that do not meet the criteria of this policy will not be considered medically necessary. A network provider cannot bill the member for the denied service unless: (a) the provider has given advance written notice, informing the member that the service may be deemed not medically necessary; (b) the member is provided with an estimate of the cost; and (c) the member agrees in writing to assume financial responsibility in advance of receiving the service. The signed agreement must be maintained in the provider’s records.
Medical policies do not constitute medical advice, nor are they intended to govern the practice of medicine. They are intended to reflect Highmark's reimbursement and coverage guidelines. Coverage for services may vary for individual members, based on the terms of the benefit contract.
Discrimination is Against the Law
The Claims Administrator/Insurer complies with applicable Federal civil rights laws and does not discriminate on the basis of race, color, national origin, age, disability, or sex. The Claims Administrator/Insurer does not exclude people or treat them differently because of race, color, national origin, age, disability, or sex. The Claims Administrator/ Insurer:
If you need these services, contact the Civil Rights Coordinator.
- Provides free aids and services to people with disabilities to communicate effectively with us, such as:
- Qualified sign language interpreters
- Written information in other formats (large print, audio, accessible electronic formats, other formats)
- Provides free language services to people whose primary language is not English, such as:
- Qualified interpreters
- Information written in other languages
If you believe that the Claims Administrator/Insurer has failed to provide these services or discriminated in another way on the basis of race, color, national origin, age, disability, or sex, you can file a grievance with: Civil Rights Coordinator, P.O. Box 22492, Pittsburgh, PA 15222, Phone: 1-866-286-8295, TTY: 711, Fax: 412-544-2475, email: CivilRightsCoordinator@highmarkhealth.org. You can file a grievance in person or by mail, fax, or email. If you need help filing a grievance, the Civil Rights Coordinator is available to help you.
You can also file a civil rights complaint with the U.S. Department of Health and Human Services, Office for Civil Rights electronically through the Office for Civil Rights Complaint Portal, available at https://ocrportal.hhs.gov/ocr/portal/lobby.jsf, or by mail or phone at:
U.S. Department of Health and Human Services
200 Independence Avenue, SW
Room 509F, HHH Building
Washington, D.C. 20201
1-800-368-1019, 800-537-7697 (TDD)
Complaint forms are available at http://www.hhs.gov/ocr/office/file/index.html.
Insurance or benefit/claims administration may be provided by Highmark, Highmark Choice Company, Highmark Coverage Advantage, Highmark Health Insurance Company, First Priority Life Insurance Company, First Priority Health, Highmark Benefits Group, Highmark Select Resources, Highmark Senior Solutions Company or Highmark Senior Health Company, all of which are independent licensees of the Blue Cross and Blue Shield Association, an association of independent Blue Cross and Blue Shield plans.
Highmark retains the right to review and update its medical policy guidelines at its sole discretion. These guidelines are the proprietary information of Highmark. Any sale, copying or dissemination of the medical policies is prohibited; however, limited copying of medical policies is permitted for individual use.