Comprehensive Muscular Dystrophy / Myopathy Panel

Last modified: Mar 21, 2018


  • Is a 73 gene panel that includes assessment of non-coding variants
  • Is ideal for patients with distal myopathy or a clinical suspicion of muscular dystrophy. Includes the smaller Nemaline Myopathy Panel, LGMD and Congenital Muscular Dystrophy Panel, Emery-Dreifuss Muscular Dystrophy Panel and Collagen Type VI-Related Disorders Panel.

Analysis methods

  • PLUS
  • SEQ


3-4 weeks

Number of genes


Test code


CPT codes

SEQ 81404
SEQ 81405
SEQ 81406
DEL/DUP 81479


The Blueprint Genetics Comprehensive Muscular Dystrophy / Myopathy Panel (test code NE0701):

  • Is a 73 gene panel that includes assessment of selected non-coding disease-causing variants
  • Is available as PLUS analysis (sequencing analysis and deletion/duplication analysis), sequencing analysis only or deletion/duplication analysis only

ICD codes

Commonly used ICD-10 code(s) when ordering the Comprehensive Muscular Dystrophy / Myopathy Panel

ICD-10 Disease
G71.0 Muscular dystrophy

Sample Requirements

  • EDTA blood, min. 1 ml
  • Purified DNA, min. 3μg
  • Saliva (Oragene DNA OG-500 kit)

Label the sample tube with your patient’s name, date of birth and the date of sample collection.

Note that we do not accept DNA samples isolated from formalin-fixed paraffin-embedded (FFPE) tissue.

Muscular dystrophies and myopathies are a complex group of neuromuscular or musculoskeletal disorders that typically result in progressive muscle weakness. The age of onset, affected muscle groups and additional symptoms depend on the type of the disease.

Limb girdle muscular dystrophy (LGMD) is a group of disorders with atrophy and weakness of proximal limb girdle muscles, typically sparing the heart and bulbar muscles. However, cardiac and respiratory impairment may be observed in certain forms of LGMD. In congenital muscular dystrophy (CMD), the onset of muscle weakness typically presents in the newborn period or early infancy. Clinical severity, age of onset, and disease progression are highly variable among the different forms of LGMD/CMD. Phenotypes overlap both within CMD subtypes and among the congenital muscular dystrophies, congenital myopathies, and LGMDs. Emery-Dreifuss muscular dystrophy (EDMD) is a condition that affects mainly skeletal muscle and heart. Usually it presents in early childhood with contractures, which restrict the movement of certain joints – most often elbows, ankles, and neck. Most patients also experience slowly progressive muscle weakness and wasting, beginning with the upper arm and lower leg muscles and progressing to shoulders and hips. Almost all patients with EDMD have cardiac involvement by adulthood. It presents clinically as cardiac conduction defects and/or arrhythmias. The cardiomyopathy phenotype is usually classified as dilated cardiomyopathy (DCM) but also ARVC and hypertrophic cardiomyopathies (HCM) have been described. A small proportion of patients with autosomal dominant EDMD experience cardiac manifestation without any skeletal muscle weakness or wasting.

Dystrophinopathies include a spectrum of muscle diseases ranging from asymptomatic with an increase in serum concentration of creatine phosphokinase to the severe progressive muscle diseases that are classified as Duchenne or Becker muscular dystrophy (DMD or BMD) when skeletal muscle is primarily affected and as DMD-associated DCM when the heart is primarily affected. DMD usually presents in early childhood with delayed milestones, including delays in sitting and standing independently. DMD is rapidly progressive, with affected children being wheelchair dependent by age 13 years and cardiomyopathy occurring soon after that. BMD is characterized by later onset skeletal muscle weakness; some individuals remain ambulatory into their 20s. However, heart failure from DCM is a common cause of death in the mid-40s. DMD-associated DCM is characterized by left ventricular dilation and congestive heart failure. Females heterozygous for a pathogenic variant in DMD are at increased risk for DCM.

The collagen type VI-related disorders are now recognized to be a continuum of overlapping phenotypes with Bethlem myopathy at the mild end and Ullrich congenital muscular dystrophy (UCMD) at the severe end. In between these phenotypes, there are collagen type VI-related limb-girdle muscular dystrophy and myosclerosis myopathy. Bethlem myopathy is characterized by proximal weakness and variable contractures. Elbows, ankles and fingers are most often affected. If the onset is in early childhood, delayed motor milestones, muscle weakness and contractures are evident. Adult onset patients require eventually ambulatory support. UCMD is characterized by congenital muscle weakness, proximal joint contractures, and striking hyperlaxity of distal joints. Affected children rarely gain the ability to walk independently and spinal rigidity and scoliosis develop. Respiratory failure is a common cause of death in the first and second decade of life. Intelligence is normal in both Bethlem myopathy and UCMD.

Nemaline Myopathy is characterized by weakness, hypotonia, and depressed or absent deep tendon reflexes. Histopathologically, nemaline bodies are detected on muscle biopsy. The clinical classification defines six forms of Nemaline Myopathy, which are classified by onset and severity of motor and respiratory involvement. Considerable overlap occurs among the forms.

Genes in the Comprehensive Muscular Dystrophy / Myopathy Panel and their clinical significance

Gene Associated phenotypes Inheritance ClinVar HGMD
ACTA1 Myopathy AD/AR 50 206
ANO5 Gnathodiaphyseal dysplasia, LGMD2L and distal MMD3 muscular dystrophies AD/AR 49 115
ATP2A1 Brody myopathy AR 7 15
B3GALNT2 Muscular dystrophy-dystroglycanopathy AR 11 13
BAG3 Dilated cardiomyopathy (DCM), Myopathy, myofibrillar AD 30 50
CAPN3 Muscular dystrophy, limb-girdle, Eosinophilic myositis AR 108 427
CAV3 Creatine phosphokinase, elevated serum, Hypertrophic cardiomyopathy (HCM), Long QT syndrome AD/Digenic 24 48
CFL2 Nemaline myopathy AR 3 5
COL4A1 Schizencephaly, Anterior segment dysgenesis with cerebral involvement, Retinal artery tortuosity, Porencephaly, Angiopathy, hereditary, with nephropathy, aneurysms, and muscle cramps, Brain small vessel disease AD 46 97
COL4A2 Hemorrhage, intracerebral AD 11 11
COL6A1 Bethlem myopathy, Ullrich congenital muscular dystrophy AD/AR 53 109
COL6A2 Epilepsy, progressive myoclonic, Bethlem myopathy, Myosclerosis, congenital, Ullrich congenital muscular dystrophy AD/AR 68 145
COL6A3 Bethlem myopathy, Dystonia, Ullrich congenital muscular dystrophy AD/AR 44 109
COL12A1 Bethlem myopathy, Ullrich congenital muscular dystrophy AD/AR 7 7
CRYAB Cataract, myofibrillar myopathy and cardiomyopathy, Congenital cataract and cardiomyopathy, Dilated cardiomyopathy (DCM), Myopathy, myofibrillar AD 16 27
DES Dilated cardiomyopathy (DCM), Myopathy, myofibrillar, Scapuloperoneal syndrome, neurogenic, Kaeser type AD/AR 57 109
DMD Becker muscular dystrophy, Duchenne muscular dystrophy, Dilated cardiomyopathy (DCM) XL 610 3620
DNAJB6 Muscular dystrophy, limb-girdle AD 10 12
DYSF Miyoshi muscular dystrophy, Muscular dystrophy, limb-girdle, Myopathy, distal, with anterior tibial onset AR 155 517
EMD Emery-Dreifuss muscular dystrophy XL 40 112
FHL1* Myopathy with postural muscle atrophy, Emery-Dreifuss muscular dystrophy, Reducing bod myopathy XL 21 59
FKRP Muscular dystrophy-dystroglycanopathy AR 36 114
FKTN Muscular dystrophy-dystroglycanopathy, Dilated cardiomyopathy (DCM), Muscular dystrophy-dystroglycanopathy (limb-girdle) AD/AR 34 53
FLNC* Myopathy AD 16 87
GAA Glycogen storage disease AR 136 528
GMPPB Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), Limb-girdle muscular dystrophy-dystroglycanopathy AR 13 29
ISPD Muscular dystrophy-dystroglycanopathy AR 23 44
ITGA7 Muscular dystrophy, congenital, due to integrin alpha-7 deficiency AR 9 6
KBTBD13 Nemaline myopathy AD 3 8
KLHL40 Nemaline myopathy AR 8 24
KLHL41 Nemaline myopathy AR 6 7
LAMA2 Muscular dystrophy, congenital merosin-deficient AR 90 256
LARGE Muscular dystrophy-dystroglycanopathy AR 15 25
LDB3 Dilated cardiomyopathy (DCM), Myopathy, myofibrillar AD 9 12
LIMS2 Muscular dystrophy, limb-girdle AR 2 3
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 211 513
LMOD3 Severe congenital nemaline myopathy, Typical nemaline myopathy AR 6 15
MEGF10 Myopathy, early-onset, areflexia, respiratory distress, and dysphagia AR 16 16
MICU1 Myopathy with extrapyramidal signs AR 9 6
MME Spinocerebellar ataxia 43, Charcot-Marie-Tooth disease, axonal, type 2T 11 19
MTM1 Myopathy, centronuclear XL 155 289
MYH7 Hypertrophic cardiomyopathy (HCM), Myopathy, myosin storage, Myopathy, distal, Dilated cardiomyopathy (DCM) AD 289 923
MYOT Myopathy, myofibrillar AD 8 16
NEB* Nemaline myopathy AR 68 285
PABPN1 Oculopharyngeal muscular dystrophy AD/AR 5 23
PNPLA2 Neutral lipid storage disease with myopathy AR 11 36
POGLUT1 Dowling-Degos disease 4, Muscular dystrophy, limb-girdle, type 2Z AD 6 12
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 92 274
POMGNT2 Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 8 AR 4 9
POMT1 Muscular dystrophy-dystroglycanopathy AR 34 85
RBCK1 Polyglucosan body myopathy AR 8 14
SELENON Muscular dystrophy, rigid spine, Myopathy, congenital, with fiber- disproportion AR 27 59
SEPT9 Amyotrophy, hereditary neuralgic AD 4 11
SGCA Muscular dystrophy, limb-girdle AR 40 99
SGCB Muscular dystrophy, limb-girdle AR 22 59
SGCD Muscular dystrophy, limb-girdle, Dilated cardiomyopathy (DCM) AR 14 20
SGCG Muscular dystrophy, limb-girdle AR 19 57
SMCHD1 Facioscapulohumeral muscular dystrophy Digenic (involving a SMCHD1 mutation and permissive D4Z4 haplotype) 37 71
SPEG Centronuclear myopathy 5 AR 5 6
SYNE1 Spinocerebellar ataxia, autosomal recessive 8 AD/AR 51 114
TCAP Muscular dystrophy, limb-girdle, Hypertrophic cardiomyopathy (HCM), Dilated cardiomyopathy (DCM) AD/AR 10 26
TMEM43 Arrhythmogenic right ventricular dysplasia, Emery-Dreifuss muscular dystrophy AD 5 20
TMEM126B Mitochondrial complex I deficiency 4 4
TNNT1 Nemaline myopathy AR 2 6
TNPO3 Muscular dystrophy, limb-girdle AD 3 3
TOR1AIP1 Muscular dystrophy with progressive weakness, distal contractures and rigid spine AD/AR 1 5
TPM2 CAP myopathy, Nemaline myopathy, Arthrogryposis, distal AD 13 38
TPM3* CAP myopathy, Nemaline myopathy, Myopathy, congenital, with fiber- disproportion AD 19 27
TRAPPC11 Limb-girdle muscular dystrophy AR 6 9
TRIM32 Bardet-Biedl syndrome, Muscular dystrophy, limb-girdle AR 11 16
TTN* Dilated cardiomyopathy (DCM), Tibial muscular dystrophy, Limb-girdle muscular dystrophy, Hereditary myopathy with early respiratory failure, Myopathy, early-onset, with fatal cardiomyopathy (Salih myopathy), Muscular dystrophy, limb-girdle, type 2J AD 576 271
VMA21 Myopathy, X-linked, with excessive autophagy XL 9 11
VPS13A Choreoacanthocytosis AR 16 113

* 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).

The sensitivity to detect variants may be limited in genes marked with an asterisk (*) or number sign (#)

Gene refers to the HGNC approved gene symbol; Inheritance refers to inheritance patterns such as autosomal dominant (AD), autosomal recessive (AR), 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 Orphanet databases.

Non-coding variants covered by the panel

Gene Genomic location HG19 HGVS RefSeq RS-number
CAPN3 Chr15:42695919 c.1746-20C>T NM_000070.2
CAPN3 Chr15:42702770 c.2185-16A>G NM_000070.2
CAPN3 Chr15:42678352 c.380-13T>A NM_000070.2
COL4A1 Chr13:110802679 c.*31G>T NM_001845.4
COL4A1 Chr13:110802678 c.*32G>T NM_001845.4
COL4A1 Chr13:110802675 c.*35C>A NM_001845.4
COL6A1 Chr21:47413935 c.1336-146C>T NM_001848.2
COL6A1 Chr21:47409881 c.930+189C>T NM_001848.2
COL6A2 Chr21:47541407 c.1459-63G>A NM_001849.3
DMD ChrX:32644479 c.1332-11909C>G NM_004006.2
DMD ChrX:32841967 c.265-463A>G NM_004006.2
DMD ChrX:33192452 c.31+36947G>A NM_004006.2
DMD ChrX:32479520 c.3432+2036A>G NM_004006.2
DMD ChrX:32479316 c.3432+2240A>G NM_004006.2
DMD ChrX:32460274 c.3787-843C>A NM_004006.2
DMD ChrX:32398808 c.4675-11A>G NM_004006.2
DMD ChrX:32827744 c.531-16T>A/G NM_004006.2
DMD ChrX:32366860 c.5326-215T>G NM_004006.2
DMD ChrX:32360414 c.5740-15G>T NM_004006.2
DMD ChrX:32274692 c.6290+30954C>T NM_004006.2
DMD ChrX:31983146 c.6614+3310G>T NM_004006.2 rs797045526
DMD ChrX:31897527 c.6913-4037T>G NM_004006.2
DMD ChrX:31627738 c.8217+18052A>G NM_004006.2
DMD ChrX:31613687 c.8217+32103G>T NM_004006.2
DMD ChrX:32716130 c.832-15A>G NM_004006.2 rs72470513
DMD ChrX:31382270 c.9085-15519G>T NM_004006.2
DMD ChrX:31332523 c.9224+9192C>A NM_004006.2
DMD ChrX:31279293 c.9225-160A>G NM_004006.2
DMD ChrX:31279418 c.9225-285A>G NM_004006.2
DMD ChrX:31279780 c.9225-647A>G NM_004006.2 rs398124091
DMD ChrX:31279781 c.9225-648A>G NM_004006.2 rs398124084
DMD ChrX:33032666 c.93+5590T>A NM_004006.2
DMD ChrX:31229031 c.9362-1215A>G NM_004006.2
DMD ChrX:31226400 c.9563+1215A>G NM_004006.2
DMD ChrX:31224814 c.9564-30A>T NM_004006.2
DMD ChrX:31225211 c.9564-427T>G NM_004006.2
DMD ChrX:32669100 c.961-5831C>T NM_004006.2 rs398124099
DMD ChrX:32669194 c.961-5925A>C NM_004006.2
DMD ChrX:31219364 c.9807+2714C>T NM_004006.2
DYSF Chr2:71817308 c.3443-33A>G NM_003494.3 rs786205083
DYSF Chr2:71840553 c.4410+13T>G NM_003494.3
DYSF Chr2:71889030 c.4886+1249G>T NM_003494.3
FKTN Chr9:108368857 c.648-1243G>T NM_006731.2
GAA Chr17:78078369 c.-17C>T NM_000152.3
GAA Chr17:78078341 c.-32-13T>A NM_000152.3
GAA Chr17:78078352 c.-32-2A>G NM_000152.3
GAA Chr17:78078351 c.-32-3C>A/G NM_000152.3
GAA Chr17:78092432 c.2647-20T>G NM_000152.3
LAMA2 Chr6:129636608 c.3556-13T>A NM_000426.3 rs775278003
LAMA2 Chr6:129714172 c.5235-18G>A NM_000426.3 rs188365084
LMNA Chr1:156107037 c.1608+14G>A NM_170707.3
LMNA Chr1:156107433 c.1609-12T>G NM_170707.3 rs267607582
LMNA Chr1:156100609 c.513+45T>G NM_170707.3
LMNA Chr1:156105681 c.937-11C>G NM_170707.3 rs267607645
MTM1 ChrX:149808833 c.529-909A>G NM_000252.2
MTM1 ChrX:149818176 c.868-13T>A NM_000252.2
NEB Chr2:152355017 c.24220-151C>A NM_001271208.1
POMT1 Chr9:134379574 c.-30-2A>G NM_007171.3
SELENON Chr1:26143316 c.*1107T>C NM_020451.2
SGCG Chr13:23755215 c.-1+1G>T NM_000231.2
SMCHD1 Chr18:2701019 c.1647+103A>G NM_015295.2
SYNE1 Chr6:152643033 c.15918-12A>G NM_182961.3 rs606231134
VMA21 ChrX:150572076 c.54-27A>C/T NM_001017980.3

Added and removed genes from the panel

Genes added Genes removed

Test strength

The strengths of this test include:
  • CAP and ISO-15189 accreditations covering all operations at Blueprint Genetics including all Whole Exome Sequencing, NGS panels and confirmatory testing
  • 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
  • Our Nucleus online portal providing transparent and easy access to quality and performance data at the patient level
  • Our publically available analytic validation demonstrating complete details of test performance
  • 1479 non-coding disease causing variants in Blueprint WES assay (please see below ‘Non-coding disease causing variants covered by this panel’)
  • Our rigorous variant classification based on modified ACMG variant classification scheme
  • Our systematic clinical interpretation workflow using proprietary software enabling accurate and traceable processing of NGS data
  • Our comprehensive clinical statements

Test limitations

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. 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
  • Mitochondrial DNA variants
  • 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
  • Stretches of mononucleotide repeats
  • Indels larger than 50bp
  • Single exon deletions or duplications
  • Variants within pseudogene regions/duplicated segments

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 and see our Analytic Validation.

The Blueprint Genetics comprehensive muscular dystrophy / myopathy panel covers classical genes associated with Bethlem myopathy, Ullrich congenital muscular dystrophy, muscular dystrophy, distal myopathy, Emery-Dreifuss muscular dystrophy, Becker muscular dystrophy, Duchenne muscular dystrophy, collagen type VI-related autosomal dominant limb-girdle muscular dystrophy, autosomal recessive myosclerosis myopathy, Walker-Warburg syndrome, Fukuyama congenital muscular dystrophy, TMEM43-related myopathies, TTN-related myopathies, x-linked myotubular myopathy, limb-girdle muscular dystrophy, congenital muscular dystrophy, muscle-eye-brain disease and nemaline myopathy. The genes on the panel have been carefully selected based on scientific literature, mutation databases and our experience.

Our panels are sliced from our high-quality whole exome sequencing data. Please see our sequencing and detection performance table for different types of alterations at the whole exome level (Table).

Assays have been validated for different starting materials including EDTA-blood, isolated DNA (no FFPE), saliva and dry blood spots (filter card) and all provide high-quality results. The diagnostic yield varies substantially depending on the assay used, referring healthcare professional, hospital and country. Blueprint Genetics' Plus Analysis (Seq+Del/Dup) maximizes the chance to find a molecular genetic diagnosis for your patient although Sequence Analysis or Del/Dup Analysis may be a cost-effective first line test if your patient's phenotype is suggestive of a specific mutation type.

Performance of Blueprint Genetics Whole Exome Sequencing (WES) assay. All individual panels are sliced from WES data.

Sensitivity % (TP/(TP+FN) Specificity %
Single nucleotide variants 99.65% (412,456/413,893) >99.99%
Insertions, deletions and indels by sequence analysis
1-10 bps 96.94% (17,070/17,608) >99.99%
11-50 bps 99.07% (957/966) >99.99%
Copy number variants (exon level dels/dups)
Clinical samples (small CNVs, n=52)
1 exon level deletion 92.3% (24/26) NA
2 exons level deletion/duplication 100.0% (11/11) NA
3-7 exons level deletion/duplication 93.3% (14/15) NA
Microdeletion/-duplication sdrs (large CNVs, n=37))
Size range (0.1-47 Mb) 100% (37/37)
Simulated CNV detection
2 exons level deletion/duplication 90.98% (7,357/8,086) 99.96%
5 exons level deletion/duplication 98.63% (7,975/8,086) 99.98%
The performance presented above reached by WES with the following coverage metrics
Mean sequencing depth at exome level 174x
Nucleotides with >20x sequencing coverage (%) 99.4%


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 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. 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 such as, 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, the customer has an access to details of the analysis, including patient specific sequencing metrics, a gene level coverage plot and a list of regions with inadequate coverage if present. This reflects our mission to build fully transparent diagnostics where customers have easy access to crucial details of the analysis process.

Clinical interpretation

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 corner stone of clinical interpretation and resulting patient management decisions. Our classifications follow the Blueprint Genetics Variant Classification Schemes based on the ACMG guideline 2015. Minor modifications were made to increase reproducibility of the variant classification and improve the clinical validity of the report. Our experience with tens of thousands of clinical cases analyzed at our laboratory allowed us to further develop the industry standard.

The final step in the analysis of sequence variants is confirmation of variants classified as pathogenic or likely pathogenic using bi-directional Sanger sequencing. Variant(s) fulfilling all of the following criteria are not Sanger confirmed: 1) the variant quality score is above the internal threshold for a true positive call, 2) an unambiguous IGV in-line with the variant call and 3) previous Sanger confirmation of the same variant at least three times at Blueprint Genetics. Reported variants of uncertain significance are confirmed with bi-directional Sanger sequencing only if the quality score is below our internally defined quality score for true positive call. Reported copy number variations with a size <10 exons are confirmed by orthogonal methods such as qPCR if the specific CNV has been seen less than three times at Blueprint Genetics.

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 used, congress abstracts and mutation databases to help our customers 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 within the family. In the case of variants of uncertain significance (VUS), we do not recommend family member risk stratification based on the VUS result. Furthermore, in the case of VUS, we do not recommend the use of genetic information in patient management or genetic counseling. For eligible cases, Blueprint Genetics offers a no charge service to investigate the role of reported VUS (VUS Clarification Service).

Our interpretation team analyzes millions of variants from thousands of individuals with rare diseases. Thus, our database, and our understanding of variants and related phenotypes, is growing by leaps and bounds. 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 health care provider at no additional cost.