Fanconi Anemia Panel

Updated
Summary
  • Is a 24 gene panel that includes assessment of non-coding variants
  • Is ideal for patients with a clinical suspicion of Fanconi anemia or Nijmegen breakage syndrome.

Analysis methods
  • PLUS
Availability

4 weeks

Number of genes

24

Test code

HE0301

Panel size

Small

CPT codes
81479

Summary

The Blueprint Genetics Fanconi Anemia Panel (test code HE0301):

ICD codes

Commonly used ICD-10 code(s) when ordering the Fanconi Anemia Panel

ICD-10 Disease
D61.09 Fanconi anemia
Q82.2 Bloom syndrome

Sample Requirements

  • Blood (min. 1ml) in an EDTA tube
  • Extracted DNA, min. 2 μg in TE buffer or equivalent
  • Saliva (Oragene DNA OG-500 kit/OGD-500 or OG-575 & OGD-575)

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. Read more about our sample requirements here.

Fanconi Anemia (FA) is a rare, inherited blood disorder that leads to bone marrow failure. The genetic defect in FA affects a cluster of proteins responsible for DNA repair. It is clinically defined by pancytopenia in the first decade of life and an increased risk of cancer, most often acute myeloid leukemia. Over half of the FA patients have congenital defects such as short stature, abnormalities of the skin, cardiac, kidney and limb malformations, radial aplasia being the most frequent. Mild microcephaly, usually without intellectual disability, is observed in 10%-25% of cases. Endocrine problems are common as well. Affected adults are also at high risk for non-hematologic malignancies. Allogeneic stem cell transplantation is the only treatment allowing long-term survival. Fanconi anemia occurs in 1 in 160,000 individuals worldwide. It is more common among people of Ashkenazi Jewish descent, the Roma population of Spain, and black South Africans. The differential diagnosis includes Seckel syndrome, Bloom syndrome and more common Nijmegen breakage syndrome (1:100,000 live births).

Genes in the Fanconi Anemia Panel and their clinical significance

Gene Associated phenotypes Inheritance ClinVar HGMD
ATM Breast cancer, Ataxia-Telangiectasia AD/AR 1047 1109
ATR Cutaneous telangiectasia and cancer syndrome, Seckel syndrome AD/AR 10 33
BLM Bloom syndrome AR 152 119
BRCA2 Fanconi anemia, Medulloblastoma, Glioma susceptibility, Pancreatic cancer, Wilms tumor, Breast-ovarian cancer, familial AD/AR 3369 2659
BRIP1 Fanconi anemia, Breast cancer AD/AR 238 189
CXCR4 Warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome AD 5 15
ERCC4 Fanconi anemia, Xeroderma pigmentosum, XFE progeroid syndrome AR 13 70
ERCC6L2 Bone marrow failure syndrome 2 AR 4 9
FANCA Fanconi anemia AR 191 677
FANCB Fanconi anemia XL 11 21
FANCC Fanconi anemia AR 94 64
FANCD2* Fanconi anemia AR 21 61
FANCE Fanconi anemia AR 4 17
FANCF Fanconia anemia AR 7 16
FANCG Fanconi anemia AR 16 92
FANCI Fanconi anemia AR 13 45
FANCL Fanconi anemia AR 13 24
FANCM Fanconi anemia AR 6 50
NBN Breast cancer, Nijmegen breakage syndrome AD/AR 188 97
PALB2 Fanconi anemia, Pancreatic cancer, Breast cancer AD/AR 495 406
RAD51C Fanconi anemia, Breast-ovarian cancer, familial AD/AR 107 125
SLX4 Fanconi anemia AR 18 72
UBE2T Fanconi anemia, complementation group T AR 2 7
XRCC2 Hereditary breast cancer AD/AR 10 21

* 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), 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 Fanconi Anemia Panel

Gene Genomic location HG19 HGVS RefSeq RS-number
ATM Chr11:108093770 c.-174A>G NM_000051.3
ATM Chr11:108094508 c.-31+595G>A NM_000051.3
ATM Chr11:108098321 c.-30-1G>T NM_000051.3 rs869312754
ATM Chr11:108138753 c.2639-384A>G NM_000051.3
ATM Chr11:108141209 c.2839-579_2839-576delAAGT NM_000051.3
ATM Chr11:108151710 c.3403-12T>A NM_000051.3 rs201370733
ATM Chr11:108158168 c.3994-159A>G NM_000051.3 rs864622543
ATM Chr11:108164028 c.4612-12A>G NM_000051.3
ATM Chr11:108179837 c.5763-1050A>G NM_000051.3 rs774925473
ATM Chr11:108214779 c.8418+681A>G NM_000051.3 rs748635985
BRCA2 Chr13:32889805 c.-40+1G>A NM_000059.3
BRCA2 Chr13:32890469 c.-39-89delC NM_000059.3
BRCA2 Chr13:32890556 c.-39-1_-39delGA NM_000059.3 rs758732038
BRCA2 Chr13:32890558 c.-39-1G>A NM_000059.3 rs1060499566
BRCA2 Chr13:32900222 c.426-12_426-8delGTTTT NM_000059.3 rs276174844
BRCA2 Chr13:32945079 c.8488-14A>G NM_000059.3
BRCA2 Chr13:32953872 c.8954-15T>G NM_000059.3
BRCA2 Chr13:32971007 c.9502-28A>G NM_000059.3 rs397508059
BRCA2 Chr13:32971023 c.9502-12T>G NM_000059.3 rs81002803
BRIP1 Chr17:59858864 c.1629-498A>T NM_032043.2
FANCA Chr16:89805127 c.4261-19_4261-12delACCTGCTC NM_000135.3
FANCA Chr16:89816056 c.3239+82T>G NM_000135.2
FANCA Chr16:89818822 c.2982-192A>G NM_000135.2
FANCA Chr16:89831215 c.2778+83C>G NM_000135.2 rs750997715
FANCA Chr16:89836111 c.2504+134A>G NM_000135.2
FANCA Chr16:89836805 c.2223-138A>G NM_000135.2
FANCA Chr16:89849346 c.1567-20A>G NM_000135.2 rs775154397
FANCA Chr16:89864654 c.893+920C>A NM_000135.2
FANCC Chr9:98011653 c.-78-2A>G NM_000136.2 rs587779898
FANCC Chr9:98079807 c.-79+1G>A NM_000136.2
FANCD2 Chr3:10083186 c.696-121C>G NM_033084.3
FANCD2 Chr3:10102127 c.1766+40T>G NM_033084.3
FANCD2 Chr3:10106024 c.1948-16T>G NM_033084.3
FANCI Chr15:89825208 c.1583+142C>T NM_001113378.1
FANCL Chr2:58433394 c.375-2033C>G NM_001114636.1
PALB2 Chr16:23649285 c.109-12T>A NM_024675.3 rs774949203

Added and removed genes from the panel

Genes added Genes removed
ERCC6L2
UBE2T

Test Strengths

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
  • 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
  • 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 (variant with a minor allele fraction of 14.6% is detected with 90% probability)
  • 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 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 96.9% (7,563/7,806) >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% (37/37)
     
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%

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. 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 <20X sequencing depth 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 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 is orthogonal confirmation. Sequence variants classified as pathogenic, likely pathogenic and variants of uncertain significance (VUS) are confirmed using bi-directional Sanger sequencing when they do not meet our stringent NGS quality metrics for a true positive call.
Reported heterozygous and homo/hemizygous copy number variations with a size <10 and <3 target exons are confirmed by orthogonal methods such as qPCR if the specific CNV has been seen and confirmed 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, 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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