Targeted mtDNA Analysis: Known Familial Mutation

Test Information

Targeted Sanger sequencing analysis for a specific variant previously identified in a family member.

Note: Levels of mutant heteroplasmy 20% or lower may not be detected by Sanger. Additionally, levels of mutant heteroplasmy above 80% will appear homoplasmic by Sanger sequencing.

 


 

Turnaround Time

14 days

CPT Code(s)

81403

Cost

$350

Variants

  • m.583G>A
  • m.616T>C
  • m.1494C>T
  • m.1555A>G
  • m.1606G>A
  • m.1630A>G
  • m.1644G>A
  • m.3243A>G
  • m.3243A>T
  • m.3256C>T
  • m.3258T>C
  • m.3260A>G
  • m.3271del
  • m.3271T>C
  • m.3280A>G
  • m.3291T>C
  • m.3302A>G
  • m.3303C>T
  • m.3376G>A
  • m.3460G>A
  • m.3635G>A
  • m.3697G>A
  • m.3700G>A
  • m.3733G>A
  • m.3890G>A
  • m.3902_3908inv
  • m.4171C>A
  • m.4298G>A
  • m.4300A>G
  • m.4308G>A
  • m.4332G>A
  • m.4450G>A
  • m.5521G>A
  • m.5537_5538insT
  • m.5650G>A
  • m.5690A>G
  • m.5703G>A
  • m.5728T>C
  • m.7445A>G
  • m.7471dup
  • m.7497G>A
  • m.7510T>C
  • m.7511T>C
  • m.8306T>C
  • m.8313G>A
  • m.8340G>A
  • m.8344A>G
  • m.8356T>C
  • m.8363G>A
  • m.8528T>C
  • m.8851T>C
  • m.8969G>A
  • m.8993T>G
  • m.8993T>C
  • m.9035T>C
  • m.9155A>G
  • m.9176T>G
  • m.9176T>C
  • m.9185T>C
  • m.9205_9206del
  • m.10010T>C
  • m.10158T>C
  • m.10191T>C
  • m.10197G>A
  • m.10663T>C
  • m.11777C>A
  • m.11778G>A
  • m.12147G>A
  • m.12258C>A
  • m.12276G>A
  • m.12294G>A
  • m.12315G>A
  • m.12316G>A
  • m.12706T>C
  • m.13042G>A
  • m.13051G>A
  • m.13094T>C
  • m.13379A>C
  • m.13513G>A
  • m.13514A>G
  • m.14459G>A
  • m.14482C>G
  • m.14482C>A
  • m.14484T>C
  • m.14487T>C
  • m.14495A>G
  • m.14568C>T
  • m.14674T>C
  • m.14709T>C
  • m.14710G>A
  • m.14849T>C
  • m.15579A>G

Clinical Information

Mitochondrial disorders represent a clinically heterogeneous group of conditions caused by pathogenic variants in either nuclear or mitochondrial DNA (mtDNA). Some mitochondrial disorders affect a single organ while most involve multiple organ systems. Mitochondrial disorders may present at any age and often present with prominent neurologic and myopathic features. Mitochondrial disorders have variable penetrance and severity of symptoms depending on the level of mutant mitochondria, or heteroplasmy, within a given individual or tissue type.

Indications

Molecular testing is useful to confirm the diagnosis of a mitochondrial condition in a family member.

Methodology

Sanger Sequencing

Detection

Analysis for a familial variant can be performed using either Sanger sequencing or Next Generation Sequencing (NGS). Sanger sequencing is only able to detect levels of heteroplasmy above 20% while NGS can detect levels as low as 10%. For this reason, Sanger sequencing may be considered as a first step in evaluating for the presence of a familial variant. NGS testing may be reserved for those who appear to be affected or who would be expected to carry the familial variant, but have had negative Sanger sequencing results. As heteroplasmy levels vary from tissue to tissue, a negative blood test cannot completely rule out the chance that an individual carries the familial variant.

Specimen Requirements

The required sample type is peripheral blood collected in an EDTA (purple top) tube - at least 2-3ml for pediatric patients and 5-6ml for adult patients.

Transport Instructions

The specimen should be kept at room temperature and delivered via overnight shipping. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.

Have Questions? Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Falecia Thomas, MS, CGC

Meet the Shenal Family

Our daughter, Ryleigh, was diagnosed with a rare chromosomal deletion shortly after she was born in 2010. Since we received her diagnosis, the Greenwood Genetic Center has become part of our family. They made certain that we did not feel alone, and they continue to provide ongoing, compassionate care for our child. The impact they have had on our family and others across the globe everyday is immeasurable. We can't imagine walking this journey without...

In The News