- Is a 153 gene panel that includes assessment of non-coding variants.
Is ideal for patients with a clinical suspicion of Charcot-Marie-Tooth neuropathy.
The Blueprint Genetics Charcot-Marie-Tooth Neuropathy Panel (test code NE1301):
Read about our accreditations, certifications and CE-marked IVD medical devices here.
Refer to the most current version of ICD-10-CM manual for a complete list of ICD-10 codes.
- Blood (min. 1ml) in an EDTA tube
- Extracted DNA, min. 2 μg in TE buffer or equivalent
- Saliva (Please see Sample Requirements for accepted saliva kits)
Label the sample tube with your patient’s name, date of birth and the date of sample collection.
We do not accept DNA samples isolated from formalin-fixed paraffin-embedded (FFPE) tissue. In addition, if the patient is affected with a hematological malignancy, DNA extracted from a non-hematological source (e.g. skin fibroblasts) is strongly recommended.
Please note that, in rare cases, mitochondrial genome (mtDNA) variants may not be detectable in blood or saliva in which case DNA extracted from post-mitotic tissue such as skeletal muscle may be a better option.
Read more about our sample requirements here.
Charcot-Marie-Tooth (CMT) neuropathy, also known as hereditary motor/sensory neuropathy (HMSN) is the most common genetic cause of neuropathy. Prevalence is estimated to be 1:3,300. CMT is characterized by broad genetic heterogeneity and can be inherited in an autosomal dominant, autosomal recessive or X-linked manner. CMT neuropathy results from involvement of peripheral nerves that can affect the motor system and/or the sensory system. Individuals with CMT experience symmetric, slowly progressive distal motor neuropathy of the arms and legs usually beginning in the first to third decade of life, and resulting in weakness and atrophy of the muscles in the feet and/or hands. Pes cavus foot deformity is common. CMT neuropathies can be divided to demyelinating and axonal forms.
Genes in the Charcot-Marie-Tooth Neuropathy Panel and their clinical significance
|AARS||Epileptic encephalopathy, early infantile, Charcot-Marie-Tooth disease||AD/AR||9||16|
|AIFM1||Deafness, Combined oxidative phosphorylation deficiency 6, Cowchock syndrome||XL||27||31|
|AMACR||Alpha-methylacyl-CoA racemase deficiency, Bile acid synthesis defect||AR||3||8|
|ARHGEF10||Slowed nerve conduction velocity||AD||4||12|
|ATL1||Spastic paraplegia, Neuropathy, hereditary sensory||AD||29||84|
|ATL3||Neuropathy, hereditary sensory||AD||1||4|
|ATP7A||Menkes disease, Occipital horn syndrome, Spinal muscular atrophy, distal, X-linked 3||XL||116||354|
|BAG3||Dilated cardiomyopathy (DCM), Myopathy, myofibrillar||AD||39||62|
|BICD2||Childhood-onset proximal spinal muscular atrophy with contractures||AD||12||28|
|BSCL2||Lipodystrophy, congenital generalized, Encephalopathy, progressive, Neuropathy, distal hereditary motor, type VA, Charcot-Marie-Tooth disease type 2, Silver syndrome, Silver spastic paraplegia syndrome, Spastic paraplegia 17||AD/AR||34||50|
|C12ORF65||Spastic paraplegia, Combined oxidative phosphorylation deficiency||AR||10||11|
|CCT5||Neuropathy, hereditary sensory, with spastic paraplegia||AR||1||1|
|CHCHD10||Myopathy, isolated mitochondrial, Frontotemporal dementia and/or amyotrophic lateral sclerosis 2, Spinal muscular atrophy, Jokela type||AD||4||26|
|COA7||Spinocerebellar ataxia, Charcot-Marie-Tooth disease||AR||2||7|
|COX10*||Leigh syndrome, Mitochondrial complex IV deficiency||AR||52||13|
|CTDP1||Congenital cataracts, facial dysmorphism, and neuropathy||AR||1||1|
|DCAF8||Giant axonal neuropathy 2, autosomal dominant||AD||1||1|
|DCTN1||Perry syndrome, Neuropathy, distal hereditary motor||AD||10||52|
|DHTKD1||2-aminoadipic and 2-oxoadipic aciduria, Charcot-Marie-Tooth disease||AD/AR||11||18|
|DNAJB2||Spinal muscular atrophy, distal, Charcot-Marie-Tooth disease||AR||9||5|
|DNM2||Myopathy, Lethal akinesia and musculoskeletal abnormalities, with brain and retinal hemorrhages, Charcot-Marie-Tooth disease||AD/AR||28||47|
|DNMT1||Neuropathy, hereditary sensory, Cerebellar ataxia, deafness, and narcolepsy||AD||9||20|
|DST||Neuropathy, hereditary sensory and autonomic||AR||13||7|
|DYNC1H1||Spinal muscular atrophy, Charcot-Marie-Tooth disease, Mental retardation||AD||60||71|
|EGR2||Neuropathy, Dejerine-Sottas disease, Charcot-Marie-Tooth disease||AD/AR||13||21|
|FAM134B||Neuropathy, hereditary sensory and autonomic||AR||8||5|
|FBLN5||Cutis laxa, Macular degeneration, age-related||AD/AR||13||22|
|FBXO38||Neuronopathy, distal hereditary motor||AD||1||5|
|FIG4||Amyotrophic lateral sclerosis, Polymicrogyria, bilateral occipital, Yunis-Varon syndrome, Charcot-Marie-Tooth disease||AD/AR||34||69|
|GAN||Giant axonal neuropathy||AR||18||76|
|GARS||Neuropathy, distal hereditary motor, Charcot-Marie-Tooth disease||AD||19||38|
|GNE||Proximal myopathy and ophthalmoplegia, Nonaka myopathy, Sialuria||AD/AR||78||214|
|GSN||Amyloidosis, Finnish type||AD||3||13|
|HADHB||Trifunctional protein deficiency||AR||20||65|
|HARS||Charcot-Marie-Tooth disease, axonal, type 2W, Usher syndrome, type 3B||AD/AR||6||12|
|HINT1||Axonal neuropathy with neuromyotonia||AR||11||15|
|HK1#||Hemolytic anemia, nonspherocytic, due to hexokinase deficiency, Retinitis pigmentosa 79, Neuropathy, motor and sensory, Russe type (Charcot-Marie-Tooth disease type 4G)||AD/AR||9||7|
|HSPB1||Neuropathy, distal hereditary motor, Charcot-Marie-Tooth disease||AD||27||44|
|HSPB8||Charcot-Marie-Tooth disease, Distal hereditary motor neuronopathy||AD||6||9|
|IGHMBP2||Spinal muscular atrophy, distal, Charcot-Marie-Tooth disease||AR||52||128|
|IKBKAP||Dysautonomia, familial, Hereditary sensory and autonomic neuropathy||AR||47||6|
|INF2||Glomerulosclerosis, Charcot-Marie-Tooth disease||AD||20||67|
|KARS||Charcot-Marie-Tooth disease, Deafness, autosomal recessive||AR||9||23|
|KIF1A||Spastic paraplegia, Neuropathy, hereditary sensory, Mental retardation||AD/AR||63||42|
|KIF1B||Pheochromocytoma, Neuroblastoma, Charcot-Marie-Tooth disease, type 2A1||AD||7||12|
|LDB3||Dilated cardiomyopathy (DCM), Myopathy, myofibrillar||AD||9||14|
|LMNA||Heart-hand syndrome, Slovenian, Limb-girdle muscular dystrophy, Muscular dystrophy, congenital, LMNA-related, Lipodystrophy (Dunnigan), Emery-Dreiffus muscular dystrophy, Malouf syndrome, Dilated cardiomyopathy (DCM), Mandibuloacral dysplasia type A, Progeria Hutchinson-Gilford type||AD/AR||250||564|
|MARS||Interstitial lung and liver disease, Charcot-Marie-Tooth disease, Charcot-Marie-Tooth disease, axonal, type 2U||AD/AR||9||13|
|MED25||Basel-Vanagait-Smirin-Yosef syndrome, Charcot-Marie-Tooth disease||AR||4||5|
|MFN2||Hereditary motor and sensory neuropathy, Charcot-Marie-Tooth disease||AD/AR||70||223|
|MME||Spinocerebellar ataxia 43, Charcot-Marie-Tooth disease, axonal, type 2T||AD/AR||14||21|
|MORC2||Charcot-Marie-Tooth disease type, axonal, type 2Z||AD||6||17|
|MPV17||Mitochondrial DNA depletion syndrome||AR||35||50|
|MPZ||Neuropathy, Roussy-Levy syndrome, Dejerine-Sottas disease, Charcot-Marie-Tooth disease||AD||108||241|
|MT-ATP6||Neuropathy, ataxia, and retinitis pigmentosa, Leber hereditary optic neuropathy, Ataxia and polyneuropathy, adult-onset, Cardiomyopathy, infantile hypertrophic, Leigh syndrome, Striatonigral degeneration, infantile, mitochondrial||Mitochondrial||19|
|MT-ATP8||Cardiomyopathy, apical hypertrophic, and neuropathy, Cardiomyopathy, infantile hypertrophic||Mitochondrial||4|
|MT-CO1||Myoglobinuria, recurrent, Leber hereditary optic neuropathy, Sideroblastic anemia, Cytochrome C oxidase deficiency, Deafness, mitochondrial||Mitochondrial||17|
|MT-CO2||Cytochrome c oxidase deficiency||Mitochondrial||8|
|MT-CO3||Cytochrome c oxidase deficiency, Leber hereditary optic neuropathy||Mitochondrial||9|
|MT-ND1||Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes, Leber hereditary optic neuropathy, Leber optic atrophy and dystonia||Mitochondrial||21|
|MT-ND2||Leber hereditary optic neuropathy, Mitochondrial complex I deficiency||Mitochondrial||6|
|MT-ND3||Leber optic atrophy and dystonia, Mitochondrial complex I deficiency||Mitochondrial||7|
|MT-ND4||Leber hereditary optic neuropathy, Leber optic atrophy and dystonia, Mitochondrial complex I deficiency||Mitochondrial||11|
|MT-ND4L||Leber hereditary optic neuropathy||Mitochondrial||2|
|MT-ND5||Myoclonic epilepsy with ragged red fibers, Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes, Leber hereditary optic neuropathy, Mitochondrial complex I deficiency||Mitochondrial||19|
|MT-ND6||Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes, Oncocytoma, Leber hereditary optic neuropathy, Leber optic atrophy and dystonia, Mitochondrial complex I deficiency||Mitochondrial||16|
|MT-TC||Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes||Mitochondrial||3|
|MT-TE||Diabetes-deafness syndrome, Mitochondrial myopathy, infantile, transient, Mitochondrial myopathy with diabetes||Mitochondrial||5|
|MT-TF||Myoclonic epilepsy with ragged red fibers, Nephropathy, tubulointerstitial, Encephalopathy, mitochondrial, Epilepsy, mitochondrial, Myopathy, mitochondrial, Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes||Mitochondrial||7|
|MT-TK||Myoclonic epilepsy with ragged red fibers, Leigh syndrome||Mitochondrial||5|
|MT-TL1||Cytochrome c oxidase deficiency, Myoclonic epilepsy with ragged red fibers, Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes, Diabetes-deafness syndrome, Cyclic vomiting syndrome, SIDS, susceptibility to||Mitochondrial||14|
|MT-TL2||Mitochondrial multisystemic disorder, Progressive external ophthalmoplegia, Mitochondrial Myopathy, Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes||Mitochondrial||5|
|MT-TM||Leigh syndrome, Mitochondrial multisystemic disorder||Mitochondrial||1|
|MT-TN||Progressive external ophthalmoplegia, Mitochondrial multisystemic disorder||Mitochondrial||3|
|MT-TQ||Mitochondrial multisystemic disorder||Mitochondrial||2|
|MT-TS1||Myoclonic epilepsy with ragged red fibers, Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes||Mitochondrial||10|
|MT-TS2||Mitochondrial multisystemic disorder||Mitochondrial||2|
|MT-TV||Hypertrophic cardiomyopathy (HCM), Leigh syndrome, Mitochondrial multisystemic disorder, Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes||Mitochondrial||3|
|MT-TW||Leigh syndrome, Myopathy, mitochondrial||Mitochondrial||8|
|MT-TY||Mitochondrial multisystemic disorder||Mitochondrial||4|
|MYOT||Myopathy, myofibrillar, Muscular dystrophy, limb-girdle, 1A, Myopathy, spheroid body||AD||6||16|
|NEFH*||Charcot-Marie-Tooth disease, axonal, type 2CC||AD/AR||4||21|
|NGF||Neuropathy, hereditary sensory and autonomic||AR||2||6|
|NTRK1||Insensitivity to pain, congenital, with anhidrosis, Medullary thyroid carcinoma, familial||AR||38||123|
|PLEKHG5||Spinal muscular atrophy, Charcot-Marie-Tooth disease||AR||16||8|
|PMP22||Neuropathy, inflammatory demyelinating, Roussy-Levy syndrome, Dejerine-Sottas disease, Neuropathy, hereditary, with liability to pressurve palsies, Charcot-Marie-Tooth disease||AD/AR||49||165|
|PNKP||Epileptic encephalopathy, early infantile, Ataxia-oculomotor||AR||34||23|
|POLG||POLG-related ataxia neuropathy spectrum disorders, Sensory ataxia, dysarthria, and ophthalmoparesis, Alpers syndrome, Progressive external ophthalmoplegia with mitochondrial DNA deletions, Mitochondrial DNA depletion syndrome||AD/AR||89||290|
|POLG2||Progressive external ophthalmoplegia with mitochondrial DNA deletions||AD||5||14|
|PRDM12||Neuropathy, hereditary sensory and autonomic, type VIII||AR||7||11|
|PRPS1*||Phosphoribosylpyrophosphate synthetase I superactivity, Arts syndrome, Charcot-Marie-Tooth disease, X-linked recessive, 5, Deafness, X-linked 1||XL||27||32|
|PRX||Dejerine-Sottas disease, Charcot-Marie-Tooth disease||AR||26||55|
|REEP1||Spastic paraplegia, Distal hereditary motor neuronopathy||AD||16||60|
|SACS||Spastic ataxia, Charlevoix-Saguenay||AR||254||262|
|SCN11A||Episodic pain syndrome, familial, 3, Neuropathy, hereditary sensory and autonomic, type VII||AD||8||20|
|SCN9A||Paroxysmal extreme pain disorder, Small fiber neuropathy, Erythermalgia, primary, Generalized epilepsy with febrile seizures plus, type 7, Insensitivity to pain, congenital, autosomal recessive||AD/AR||61||125|
|SCYL1||Spinocerebellar ataxia, autosomal recessive 21||AR||12||6|
|SEPT9||Amyotrophy, hereditary neuralgic||AD||4||11|
|SETX||Ataxia with oculomotor apraxia, Amyotrophic lateral sclerosis, juvenile, Spinocerebellar ataxia||AD/AR||36||210|
|SH3TC2||Mononeuropathy of the median nerve, Charcot-Marie-Tooth disease||AR||63||89|
|SLC12A6||Agenesis of the corpus callosum with peripheral neuropathy (Andermann syndrome)||AD/AR||43||19|
|SLC25A46||Neuropathy, hereditary motor and sensory, type VIB||AR||14||17|
|SLC52A2||Brown-Vialetto-Van Laere syndrome||AR||27||25|
|SLC52A3||Fazio-Londe disease, Brown-Vialetto-Van Laere syndrome||AR||30||42|
|SMAD3||Aneurysms-osteoarthritis syndrome, Loeys-Dietz syndrome||AD||48||82|
|SPG11||Spastic paraplegia, Amyotrophic lateral sclerosis, Charcot-Marie-Tooth disease||AR||162||274|
|SPTBN4||Myopathy, congenital, with neuropathy and deafness||AR||6||7|
|SPTLC1*||Neuropathy, hereditary sensory and autonomic||AD||8||11|
|SPTLC2||Hereditary sensory and autonomic neuropathy||AD||5||14|
|SURF1||Leigh syndrome, Charcot-Marie-Tooth disease||AR||50||101|
|TFG||Spastic paraplegia, Hereditary motor and sensory neuropathy, proximal||AR||4||7|
|TRPV4||Metatropic dysplasia, Spondyloepiphyseal dysplasia Maroteaux type, Parastremmatic dwarfism, Hereditary motor and sensory neuropathy, Spondylometaphyseal dysplasia Kozlowski type, Spinal muscular atrophy, Charcot-Marie-Tooth disease, Brachyolmia (autosomal dominant type), Familial Digital arthropathy with brachydactyly||AD||61||78|
|TTR||Dystransthyretinemic hyperthyroxinemia, Amyloidosis, hereditary, transthyretin-related||AD||52||148|
|TYMP||Mitochondrial DNA depletion syndrome||AR||84||94|
|UBA1||Spinal muscular atrophy, infantile||XL||3||5|
|VCP||Amyotrophic lateral sclerosis, Inclusion body myopathy with early-onset Paget disease, Charcot-Marie-Tooth disease||AD||17||61|
|WNK1||Neuropathy, hereditary sensory and autonomic, Pseudohypoaldosteronism||AD/AR||14||9|
|ZFYVE26||Spastic paraplegia 15||AR||63||39|
Some, or all, of the gene is duplicated in the genome. Read more.
The gene has suboptimal coverage (means <90% of the gene’s target nucleotides are covered at >20x with mapping quality score (MQ>20) reads), and/or the gene has exons listed under Test limitations section that are not included in the panel as they are not sufficiently covered with high quality sequence reads.
The sensitivity to detect variants may be limited in genes marked with an asterisk (*) or number sign (#). Due to possible limitations these genes may not be available as single gene tests.
Gene refers to the HGNC approved gene symbol; Inheritance refers to inheritance patterns such as autosomal dominant (AD), autosomal recessive (AR), mitochondrial (mi), X-linked (XL), X-linked dominant (XLD) and X-linked recessive (XLR); ClinVar refers to the number of variants in the gene classified as pathogenic or likely pathogenic in this database (ClinVar); HGMD refers to the number of variants with possible disease association in the gene listed in Human Gene Mutation Database (HGMD). The list of associated, gene specific phenotypes are generated from CGD or Mitomap databases.
Non-coding variants covered by Charcot-Marie-Tooth Neuropathy Panel
|Gene||Genomic location HG19||HGVS||RefSeq||RS-number|
Added and removed genes from the panel
|Genes added||Genes removed|
|CYP27A1 DNAJB2 FBXO38 GSN MPV17 PMP2 PNKP POLG2 SLC52A2 SLC52A3 UBA1 MT-ATP6 MT-ATP8 MT-CO1 MT-CO2 MT-CO3 MT-CYB MT-ND1 MT-ND2 MT-ND3 MT-ND4 MT-ND4L MT-ND5 MT-ND6 MT-RNR1 MT-RNR2 MT-TA MT-TC MT-TD MT-TE MT-TF MT-TG MT-TH MT-TI MT-TK MT-TL1 MT-TL2 MT-TM MT-TN MT-TP MT-TQ MT-TR MT-TS1 MT-TS2 MT-TT MT-TV MT-TW MT-TY|
The strengths of this test include:
- CAP accredited laboratory
- CLIA-certified personnel performing clinical testing in a CLIA-certified laboratory
- Powerful sequencing technologies, advanced target enrichment methods and precision bioinformatics pipelines ensure superior analytical performance
- Careful construction of clinically effective and scientifically justified gene panels
- Some of the panels include the whole mitochondrial genome (please see the Panel Content section)
- Our Nucleus online portal providing transparent and easy access to quality and performance data at the patient level
- ~2,000 non-coding disease causing variants in our clinical grade NGS assay for panels (please see ‘Non-coding disease causing variants covered by this panel’ in the Panel Content section)
- Our rigorous variant classification scheme
- Our systematic clinical interpretation workflow using proprietary software enabling accurate and traceable processing of NGS data
- Our comprehensive clinical statements
The following exons are not included in the panel as they are not sufficiently covered with high quality sequence reads: HK1 (NM_001322365:5). Genes with suboptimal coverage in our assay are marked with number sign (#) and genes with partial, or whole gene, segmental duplications in the human genome are marked with an asterisk (*) if they overlap with the UCSC pseudogene regions. Gene is considered to have suboptimal coverage when >90% of the gene’s target nucleotides are not covered at >20x with mapping quality score (MQ>20) reads. The technology may have limited sensitivity to detect variants in genes marked with these symbols (please see the Panel content table above).
This test does not detect the following:
- Complex inversions
- Gene conversions
- Balanced translocations
- Some of the panels include the whole mitochondrial genome but not all (please see the Panel Content section)
- Repeat expansion disorders unless specifically mentioned
- Non-coding variants deeper than ±20 base pairs from exon-intron boundary unless otherwise indicated (please see above Panel Content / non-coding variants covered by the panel).
This test may not reliably detect the following:
- Low level mosaicism in nuclear genes (variant with a minor allele fraction of 14.6% is detected with 90% probability)
- Stretches of mononucleotide repeats
- Low level heteroplasmy in mtDNA (>90% are detected at 5% level)
- Indels larger than 50bp
- Single exon deletions or duplications
- Variants within pseudogene regions/duplicated segments
- Some disease causing variants present in mtDNA are not detectable from blood, thus post-mitotic tissue such as skeletal muscle may be required for establishing molecular diagnosis.
The sensitivity of this test may be reduced if DNA is extracted by a laboratory other than Blueprint Genetics.
For additional information, please refer to the Test performance section.
The genes on the panel have been carefully selected based on scientific literature, mutation databases and our experience.
Our panels are sectioned from our high-quality, clinical grade NGS assay. Please see our sequencing and detection performance table for details regarding our ability to detect different types of alterations (Table).
Assays have been validated for various sample types including EDTA-blood, isolated DNA (excluding from formalin fixed paraffin embedded tissue), saliva and dry blood spots (filter cards). These sample types were selected in order to maximize the likelihood for high-quality DNA yield. The diagnostic yield varies depending on the assay used, referring healthcare professional, hospital and country. Plus analysis increases the likelihood of finding a genetic diagnosis for your patient, as large deletions and duplications cannot be detected using sequence analysis alone. Blueprint Genetics’ Plus Analysis is a combination of both sequencing and deletion/duplication (copy number variant (CNV)) analysis.
The performance metrics listed below are from an initial validation performed at our main laboratory in Finland. The performance metrics of our laboratory in Seattle, WA, are equivalent.
Performance of Blueprint Genetics high-quality, clinical grade NGS sequencing assay for panels.
|Sensitivity % (TP/(TP+FN)||Specificity %|
|Single nucleotide variants||99.89% (99,153/99,266)||>99.9999%|
|Insertions, deletions and indels by sequence analysis|
|1-10 bps||99.2% (7,745/7,806)||>99.9999%|
|11-50 bps||99.13% (2,524/2,546)||>99.9999%|
|Copy number variants (exon level dels/dups)|
|1 exon level deletion (heterozygous)||100% (20/20)||NA|
|1 exon level deletion (homozygous)||100% (5/5)||NA|
|1 exon level deletion (het or homo)||100% (25/25)||NA|
|2-7 exon level deletion (het or homo)||100% (44/44)||NA|
|1-9 exon level duplication (het or homo)||75% (6/8)||NA|
|Simulated CNV detection|
|5 exons level deletion/duplication||98.7%||100.00%|
|Microdeletion/-duplication sdrs (large CNVs, n=37))|
|Size range (0.1-47 Mb)||100% (25/25)|
|The performance presented above reached by Blueprint Genetics high-quality, clinical grade NGS sequencing assay with the following coverage metrics|
|Mean sequencing depth||143X|
|Nucleotides with >20x sequencing coverage (%)||99.86%|
Performance of Blueprint Genetics Mitochondrial Sequencing Assay.
|Sensitivity %||Specificity %|
|ANALYTIC VALIDATION (NA samples; n=4)|
|Single nucleotide variants|
|Heteroplasmic (45-100%)||100.0% (50/50)||100.0%|
|Heteroplasmic (35-45%)||100.0% (87/87)||100.0%|
|Heteroplasmic (25-35%)||100.0% (73/73)||100.0%|
|Heteroplasmic (15-25%)||100.0% (77/77)||100.0%|
|Heteroplasmic (10-15%)||100.0% (74/74)||100.0%|
|Heteroplasmic (5-10%)||100.0% (3/3)||100.0%|
|Heteroplasmic (<5%)||50.0% (2/4)||100.0%|
|CLINICAL VALIDATION (n=76 samples)|
|Single nucleotide variants n=2026 SNVs|
|Heteroplasmic (45-100%)||100.0% (1940/1940)||100.0%|
|Heteroplasmic (35-45%)||100.0% (4/4)||100.0%|
|Heteroplasmic (25-35%)||100.0% (3/3)||100.0%|
|Heteroplasmic (15-25%)||100.0% (3/3)||100.0%|
|Heteroplasmic (10-15%)||100.0% (9/9)||100.0%|
|Heteroplasmic (5-10%)||92.3% (12/13)||99.98%|
|Heteroplasmic (<5%)||88.9% (48/54)||99.93%|
|Insertions and deletions by sequence analysis n=40 indels|
|Heteroplasmic (45-100%) 1-10bp||100.0% (32/32)||100.0%|
|Heteroplasmic (5-45%) 1-10bp||100.0% (3/3)||100.0%|
|Heteroplasmic (<5%) 1-10bp||100.0% (5/5)||99,997%|
|SIMULATION DATA /(mitomap mutations)|
|Insertions, and deletions 1-24 bps by sequence analysis; n=17|
|Homoplasmic (100%) 1-24bp||100.0% (17/17)||99.98%|
|Heteroplasmic (50%)||100.0% (17/17)||99.99%|
|Heteroplasmic (25%)||100.0% (17/17)||100.0%|
|Heteroplasmic (20%)||100.0% (17/17)||100.0%|
|Heteroplasmic (15%)||100.0% (17/17)||100.0%|
|Heteroplasmic (10%)||94.1% (16/17)||100.0%|
|Heteroplasmic (5%)||94.1% (16/17)||100.0%|
|Copy number variants (separate artifical mutations; n=1500)|
|Homoplasmic (100%) 500 bp, 1kb, 5 kb||100.0%||100.0%|
|Heteroplasmic (50%) 500 bp, 1kb, 5 kb||100.0%||100.0%|
|Heteroplasmic (30%) 500 bp, 1kb, 5 kb||100.0%||100.0%|
|Heteroplasmic (20%) 500 bp, 1kb, 5 kb||99.7%||100.0%|
|Heteroplasmic (10%) 500 bp, 1kb, 5 kb||99.0%||100.0%|
|The performance presented above reached by following coverage metrics at assay level (n=66)|
|Mean of medians||Median of medians|
|Mean sequencing depth MQ0 (clinical)||18224X||17366X|
|Nucleotides with >1000x MQ0 sequencing coverage (%) (clinical)||100%|
|rho zero cell line (=no mtDNA), mean sequencing depth||12X|
The target region for each gene includes coding exons and ±20 base pairs from the exon-intron boundary. In addition, the panel includes non-coding and regulatory variants if listed above (Non-coding variants covered by the panel). Some regions of the gene(s) may be removed from the panel if specifically mentioned in the ‘Test limitations” section above. If the test includes the mitochondrial genome the target region gene list contains the mitochondrial genes. The sequencing data generated in our laboratory is analyzed with our proprietary data analysis and annotation pipeline, integrating state-of-the art algorithms and industry-standard software solutions. Incorporation of rigorous quality control steps throughout the workflow of the pipeline ensures the consistency, validity and accuracy of results. Our pipeline is streamlined to maximize sensitivity without sacrificing specificity. We have incorporated a number of reference population databases and mutation databases including, but not limited, to 1000 Genomes Project, gnomAD, ClinVar and HGMD into our clinical interpretation software to make the process effective and efficient. For missense variants, in silico variant prediction tools such as SIFT, PolyPhen,MutationTaster are used to assist with variant classification. Through our online ordering and statement reporting system, Nucleus, ordering providers have access to the details of the analysis, including patient specific sequencing metrics, a gene level coverage plot and a list of regions with suboptimal coverage (<20X for nuclear genes and <1000X for mtDNA) if applicable. This reflects our mission to build fully transparent diagnostics where ordering providers can easily visualize the crucial details of the analysis process.
We provide customers with the most comprehensive clinical report available on the market. Clinical interpretation requires a fundamental understanding of clinical genetics and genetic principles. At Blueprint Genetics, our PhD molecular geneticists, medical geneticists, and clinical consultants prepare the clinical statement together by evaluating the identified variants in the context of the phenotypic information provided in the requisition form. Our goal is to provide clinically meaningful statements that are understandable for all medical professionals regardless of whether they have formal training in genetics.
Variant classification is the cornerstone of clinical interpretation and resulting patient management decisions. Our classifications follow the ACMG guideline 2015.
The final step in the analysis is orthogonal confirmation. Sequence and copy number variants classified as pathogenic, likely pathogenic, and variants of uncertain significance (VUS) are confirmed using bi-directional Sanger sequencing or by orthogonal methods such as qPCR/ddPCR when they do not meet our stringent NGS quality metrics for a true positive call.
Our clinical statement includes tables for sequencing and copy number variants that include basic variant information (genomic coordinates, HGVS nomenclature, zygosity, allele frequencies, in silico predictions, OMIM phenotypes, and classification of the variant). In addition, the statement includes detailed descriptions of the variant, gene, and phenotype(s) including the role of the specific gene in human disease, the mutation profile, information about the gene’s variation in population cohorts, and detailed information about related phenotypes. We also provide links to the references, abstracts, and variant databases used to help ordering providers further evaluate the reported findings if desired. The conclusion summarizes all of the existing information and provides our rationale for the classification of the variant.
Identification of pathogenic or likely pathogenic variants in dominant disorders or their combinations in different alleles in recessive disorders are considered molecular confirmation of the clinical diagnosis. In these cases, family member testing can be used for risk stratification. We do not recommend using variants of uncertain significance (VUS) for family member risk stratification or patient management. Genetic counseling is recommended.
Our interpretation team analyzes millions of variants from thousands of individuals with rare diseases. Our internal database and our understanding of variants and related phenotypes increases with every case analyzed. Our laboratory is therefore well-positioned to re-classify previously reported variants as new information becomes available. If a variant previously reported by Blueprint Genetics is re-classified, our laboratory will issue a follow-up statement to the original ordering healthcare provider at no additional cost, according to our latest follow-up reporting policy.
- CMT United Kingdom
- Charcot-Marie-Tooth Association
- Charcot-Marie-Tooth Association Australia
- GeneReviews - Charcot-Marie-Tooth Hereditary Neuropathy Overview
- GeneReviews - Charcot-Marie-Tooth Neuropathy Type 1
- GeneReviews - Charcot-Marie-Tooth Neuropathy Type 2
- GeneReviews - Charcot-Marie-Tooth Neuropathy Type 4
- GeneReviews - Charcot-Marie-Tooth Neuropathy X Type 1
- Hereditary Neuropathy Foundation
- NORD - Charcot-Marie-Tooth Disease
- National Organization for Rare Disorders (NORD)