Noonan Syndrome Panel

Summary
  • Is a 35 gene panel that includes assessment of non-coding variants.
  • Is ideal for patients with a clinical suspicion of a RASopathy including Noonan syndrome with or without lentigines, cardio-facio-cutaneous (CFC) syndrome, Costello syndrome, Noonan-like syndromes or other syndromes causing differential diagnostic challenges such as Legius syndrome, Baraitser-Winter syndromes and neurofibromatosis.

Analysis methods
  • PLUS
Availability

4 weeks

Number of genes

35

Test code

CA0501

Panel size

Large

CPT code *
81442(1)
* The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

Summary

The Blueprint Genetics Noonan Syndrome Panel (test code CA0501):

Test Specific Strength

This Panel covers many recently discovered rasopathy genes such as RRAS, PPP1CB, NRAS, and RASA2 not included in most panels in the market and provides wider differential diagnostics (Baraitser-Winter syndrome, NF1 and Legius syndrome).

ICD codes

Commonly used ICD-10 code(s) when ordering the Noonan Syndrome Panel

ICD-10 Disease
Q87.1 Noonan syndrome
Q87.89 Costello syndrome
Q87.1 LEOPARD syndrome
Q87.89 Cardiofaciocutaneous syndrome

Sample Requirements

  • 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.

Noonan syndrome is one of the most common syndromes with an estimated prevalence of 1 in 1,000 to 1 in 2,500 live births. It is clinically and genetically heterogeneous condition characterized by cardiovascular abnormalities, distinctive facial features, chest deformity, short stature, and other co-morbidities. Among the Noonan syndrome associated genes, many different genotype-phenotype correlations have been established although no phenotypic features are exclusively associated with one genotype. There are, however, significant differences in the risk of various Noonan syndrome manifestations based on the causative gene.

Genes in the Noonan Syndrome Panel and their clinical significance

Gene Associated phenotypes Inheritance ClinVar HGMD
ACTB* Baraitser-Winter syndrome AD 55 60
ACTG1* Deafness, Baraitser-Winter syndrome AD 27 47
BRAF* LEOPARD syndrome, Noonan syndrome, Cardiofaciocutaneous syndrome AD 134 65
CBL Noonan syndrome-like disorder with or without juvenile myelomonocytic leukemia AD 24 43
CCNK Intellectual disability AD
CDC42* Takenouchi-Kosaki syndrome, Noonan-syndrome like phenotype AD 11 9
EPHB4 Hydrops fetalis, nonimmune, and/or atrial septal defect, Capillary malformation-arteriovenous malformation AD 1 51
FGD1 Aarskog-Scott syndrome, Mental retardation, syndromic XL 29 51
HRAS Costello syndrome, Congenital myopathy with excess of muscle spindles AD 43 31
KAT6B Ohdo syndrome, SBBYS variant, Genitopatellar syndrome AD 47 73
KRAS* Noonan syndrome, Cardiofaciocutaneous syndrome AD 63 35
LZTR1 Schwannomatosis, Noonan syndrome AD/AR 34 71
MAP2K1 Cardiofaciocutaneous syndrome AD 45 23
MAP2K2 Cardiofaciocutaneous syndrome AD 21 35
MAP3K8 Noonan syndrome AD 1
MRAS Noonan syndrome AD 1 2
NF1* Watson syndrome, Neurofibromatosis, Neurofibromatosis-Noonan syndrome AD 1157 2901
NF2 Schwannomatosis, Neurofibromatosis AD 66 433
NRAS Noonan syndrome AD 31 14
NSUN2 Dubowitz syndrome, Non-syndromic intellectual disability AD/AR 8 7
PPP1CB Noonan syndrome-like disorder with loose anagen hair 2 AD 8 11
PTPN11 Noonan syndrome, Metachondromatosis AD 135 140
RAF1 LEOPARD syndrome, Noonan syndrome, Dilated cardiomyopathy (DCM) AD 45 53
RASA1 Parkes Weber syndrome, Capillary malformation-arteriovenous malformation, Spinal arteriovenous anomalies AD 55 132
RASA2 Noonan syndrome AD 1 3
RIT1 Noonan syndrome AD 23 26
RRAS Noonan-syndrome like phenotype AD/AR 2
SASH1 Dyschromatosis universalis hereditaria AD 1 12
SHOC2 Noonan-like syndrome with loose anagen hair AD 2 4
SMARCB1 Schwannomatosis, Rhabdoid tumor predisposition syndrome, Coffin-Siris syndrome 3 AD 36 118
SOS1 Noonan syndrome AD 44 71
SOS2 Noonan syndrome 9 AD 4 6
SPRED1 Legius syndrome AD 38 71
STAMBP Microcephaly-capillary malformation syndrome AR 15 19
SYNGAP1 Mental retardation AD 102 83

* 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 (#)

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 Noonan Syndrome Panel

Gene Genomic location HG19 HGVS RefSeq RS-number
FGD1 ChrX:54476768 c.2016-35delA NM_004463.2
LZTR1 Chr22:21336623 c.-38T>A NM_006767.3
LZTR1 Chr22:21350968 c.2220-17C>A NM_006767.3 rs1249726034
NF1 Chr17:29422055 c.-273A>C NM_001042492.2
NF1 Chr17:29422056 c.-272G>A NM_001042492.2
NF1 Chr17:29431417 c.60+9031_60+9035delAAGTT NM_001042492.2
NF1 Chr17:29475515 c.61-7486G>T NM_001042492.2
NF1 Chr17:29488136 c.288+2025T>G NM_001042492.2
NF1 Chr17:29508426 c.587-14T>A NM_001042492.2
NF1 Chr17:29508428 c.587-12T>A NM_001042492.2
NF1 Chr17:29510334 c.888+651T>A NM_001042492.2
NF1 Chr17:29510427 c.888+744A>G NM_001042492.2
NF1 Chr17:29510472 c.888+789A>G NM_001042492.2
NF1 Chr17:29527428 c.889-12T>A NM_001042492.2
NF1 Chr17:29530107 c.1260+1604A>G NM_001042492.2
NF1 Chr17:29533239 c.1261-19G>A NM_001042492.2
NF1 Chr17:29534143 c.1392+754T>G NM_001042492.2
NF1 Chr17:29540877 c.1393-592A>G NM_001042492.2
NF1 Chr17:29542762 c.1527+1159C>T NM_001042492.2
NF1 Chr17:29548419 c.1642-449A>G NM_001042492.2 rs863224655
NF1 Chr17:29549489 c.*481A>G NM_001128147.2
NF1 Chr17:29553439 c.2002-14C>G NM_001042492.2
NF1 Chr17:29554225 c.2252-11T>G NM_001042492.2
NF1 Chr17:29556025 c.2410-18C>G NM_001042492.2
NF1 Chr17:29556027 c.2410-16A>G NM_001042492.2
NF1 Chr17:29556028 c.2410-15A>G NM_001042492.2
NF1 Chr17:29556031 c.2410-12T>G NM_001042492.2
NF1 Chr17:29556839 c.2851-14_2851-13insA NM_001042492.2
NF1 Chr17:29557267 c.2991-11T>G NM_001042492.2
NF1 Chr17:29558777 c.3198-314G>A NM_001042492.2
NF1 Chr17:29563299 c.3974+260T>G NM_001042492.2
NF1 Chr17:29577082 c.4110+945A>G NM_001042492.2
NF1 Chr17:29580296 c.4173+278A>G NM_001042492.2
NF1 Chr17:29588708 c.4578-20_4578-18delAAG NM_001042492.2
NF1 Chr17:29588715 c.4578-14T>G NM_001042492.2
NF1 Chr17:29654479 c.5269-38A>G NM_001042492.2
NF1 Chr17:29656858 c.5610-456G>T NM_001042492.2
NF1 Chr17:29657848 c.5812+332A>G NM_001042492.2 rs863224491
NF1 Chr17:29661577 c.5813-279A>G NM_001042492.2
NF1 Chr17:29664375 c.6428-11T>G NM_001042492.2
NF1 Chr17:29664618 c.6642+18A>G NM_001042492.2
NF1 Chr17:29676126 c.7190-12T>A NM_001042492.2
NF1 Chr17:29676127 c.7190-11_7190-10insGTTT NM_001042492.2
NF1 Chr17:29685177 c.7971-321C>G NM_001042492.2
NF1 Chr17:29685481 c.7971-17C>G NM_001042492.2
NF1 Chr17:29685665 c.8113+25A>T NM_001042492.2
NF2 Chr22:30050946 c.516+232G>A NM_000268.3
NSUN2 Chr5:6622224 c.538-11T>G NM_017755.5
PTPN11 Chr12:112915602 c.934-59T>A NM_002834.3
SMARCB1 Chr22:24130008 c.93+559A>G NM_003073.3
SMARCB1 Chr22:24176316 c.1119-12C>G NM_003073.3
SMARCB1 Chr22:24176437 c.*70C>T NM_003073.3
SMARCB1 Chr22:24176449 c.*82C>T NM_003073.3
STAMBP Chr2:74077998 c.1005+358A>G NM_006463.4

Test Strengths

This Panel covers many recently discovered rasopathy genes such as RRAS, PPP1CB, NRAS, and RASA2 not included in most panels in the market and provides wider differential diagnostics (Baraitser-Winter syndrome, NF1 and Legius syndrome).

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
  • Our publicly available analytic validation demonstrating complete details of test performance
  • ~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

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
  • 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 and see our Analytic Validation.

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.

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)
All types
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

Bioinformatics

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.

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 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 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 health care provider at no additional cost.

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