- Is a 54 gene panel that includes assessment of non-coding variants
Is ideal for patients with a clinical suspicion of cobalamin deficiency, homocystinuria, maple syrup urine disease, methylmalonic acidemia, organic acidemia/aciduria or propionic acidemia. The genes on this panel are included in the Comprehensive Metabolism Panel.
The Blueprint Genetics Organic Acidemia/Aciduria & Cobalamin Deficiency Panel (test code ME0901):
Commonly used ICD-10 code(s) when ordering the Organic Acidemia/Aciduria & Cobalamin Deficiency Panel
|E71.0||Maple syrup urine disease|
|E71.311||Multiple acyl-CoA dehydrogenase deficiency|
- 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.
Organic acidemia and aciduria refer to many disorders, where non-amino organic acids are excreted in urine. This is usually a result of deficient enzyme activity in amino acid catabolism. The clinical presentation of organic acidemia in young children includes neurologic symptoms, poor feeding and lethargy progressing to coma. Older persons with this disorder often also have neurological signs, recurrent ketoacidosis and loss of intellectual function. The symptoms result from the damaging accumulation of precursors of the defective pathway. The combined prevalence of organic acidurias is estimated at 1:1,000 newborns. Cobalamin, also known as vitamin B12, has cobalt in its structure. Humans are not able to synthesize B12. It must therefore be obtained from a food of animal origin (the only natural source of cobalamin in the human diet). Intracellular cobalamin deficiencies can be subgrouped based on the cellular complementation groups and defective genes. Mutations in genes MMAA, MMAB and MMADHC cause deficient synthesis of the coenzyme adenosylcobalamin (AdoCbl), while mutations in genes MMADHC, MTRR and MTR cause defective methylcobalamin (MeCbl) synthesis. Mutation in genes MMACHC, MMADHC, LMBRD1 and ABCD4 result in combined AdoCbl and MeCbl deficiency. Mutations in MMACHC explain approximately 80% of the cases with intracellular cobalamin deficiency, followed by MMADHC (<5%), TRR (<5%), LMBRD1 (<5%), MTR (<5%) and ABCD4 (<1%). The presentation of cobalamin deficiency can be perinatal in onset or during childhood or adulthood. The symptoms are wide ranging based on the complementation group and gene affected. Perinatal onset is characterized by growth restriction, microcephaly, heart disease and dysmorphic features. This presentation is often severe and may be lethal. Babies with cobalamin deficiency often have poor feeding, hypotonia, seizures and multiorgan involvement. Cobalamin deficiency in adulthood often presents with neurological and neuropsychiatric problems. Some specific types of cobalamin deficiencies are extremely rare with only dozens of patients described. The combined prevalence is estimated at >1:100,000.
Genes in the Organic Acidemia/Aciduria & Cobalamin Deficiency Panel and their clinical significance
|ABCD4||Methylmalonic aciduria and homocystinuria||AR||6||7|
|ACADSB||2-methylbutyryl-CoA dehydrogenase deficiency||AR||8||12|
|ACSF3||Combined malonic and methylmalonic aciduria||AR||18||22|
|ADK||Hypermethioninemia due to adenosine kinase deficiency||AD||6||14|
|AHCY||Hypermethioninemia with S-adenosylhomocysteine hydrolase deficiency||AR||3||9|
|AMN||Megaloblastic anemia-1, Norwegian||AR||29||34|
|BCKDHA||Maple syrup urine disease||AR||57||98|
|BCKDHB||Maple syrup urine disease||AR||87||103|
|BCS1L||Bjornstad syndrome, GRACILE syndrome, Leigh syndrome, Mitochondrial complex III deficiency, nuclear type 1||AR||42||37|
|CBS||Homocystinuria due to cystathionine beta-synthase deficiency||AR||88||205|
|CD320||Methylmalonic aciduria due to transcobalamin receptor defect||AR||2|
|CLPB||3-methylglutaconic aciduria with cataracts, neurologic involvement, and neutropenia (MEGCANN)||AR||26||25|
|CUBN*||Megaloblastic anemia-1, Finnish||AR||42||53|
|D2HGDH||D-2-hydroxyglutaric aciduria 1||AR||13||33|
|DBT||Maple syrup urine disease||AR||39||75|
|DLD||Dihydrolipoyl dehydrogenase deficiency||AR||36||21|
|ETFA||Glutaric aciduria, Multiple acyl-CoA dehydrogenase deficiency||AR||8||29|
|ETFB||Glutaric aciduria, Multiple acyl-CoA dehydrogenase deficiency||AR||6||15|
|ETFDH||Glutaric aciduria, Multiple acyl-CoA dehydrogenase deficiency||AR||43||190|
|FLAD1||Lipid storage myopathy due to FLAD1 deficiency (LSMFLAD)||AR||9||10|
|GIF||Intrinsic factor deficiency||AR||7||22|
|GNMT||Glycine N-methyltransferase deficiency||AR||3||5|
|HCFC1||Combined methylmalonic acidemia and hyperhomocysteinemia||XL||9||17|
|HIBCH||3-hydroxyisobutryl-CoA hydrolase deficiency||AR||18||16|
|HMGCL||3-hydroxy-3-methylglutaryl-CoA lyase deficiency||AR||24||60|
|IDH2||D-2-hydroxyglutaric aciduria 2||AD||10||4|
|LMBRD1||Methylmalonic aciduria and homocystinuria||AR||4||9|
|MCCC1||3-Methylcrotonyl-CoA carboxylase 1 deficiency||AR||40||105|
|MCCC2||3-Methylcrotonyl-CoA carboxylase 2 deficiency||AR||24||114|
|MCEE||Methylmalonyl-CoA epimerase deficiency||AR||1||4|
|MLYCD||Malonyl-CoA decarboxylase deficiency||AR||14||38|
|MMACHC||Methylmalonic aciduria and homocystinuria||AR||59||93|
|MMADHC||Methylmalonic aciduria and homocystinuria||AR||16||13|
|MTHFR||Homocystinuria due to MTHFR deficiency||AR||65||122|
|MTRR||Homocystinuria-megaloblastic anemia, cobalamin E||AR||10||31|
|MUT||Methylmalonic acidemia due to methylmalonyl-CoA mutase deficiency||AR||159||366|
|SERAC1||3-methylglutaconic aciduria with deafness, encephalopathy, and Leigh-like syndrome||AR||22||52|
|SLC25A1||Combined D-2- and L-2-hydroxyglutaric aciduria||AR||8||24|
|SUCLA2||Mitochondrial DNA depletion syndrome||AR||9||29|
|SUCLG1||Mitochondrial DNA depletion syndrome||AR||12||28|
|SUGCT||Glutaric aciduria III||AR||6||7|
|TCN2||Transcobalamin II deficiency||AR||9||35|
* 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 Organic Acidemia/Aciduria & Cobalamin Deficiency Panel
|Gene||Genomic location HG19||HGVS||RefSeq||RS-number|
Added and removed genes from the panel
|Genes added||Genes removed|
- CAP and ISO-15189 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 below ‘Non-coding disease causing variants covered by this panel’)
- 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: PCCB (NM_001178014:4). 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).
- 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).
- 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 Blueprint Genetics organic acidemia/Aciduria & cobalamin deficiency panel covers classical genes associated with organic acidemia/aciduria, maple syrup urine disease, propionic acidemia, methylmalonic acidemia, cobalamin deficiency, homocystinuria, isovaleric acidemia, transcobalamin receptor defect, DLD deficiency and multiple acyl-CoA dehydrogenase deficiency. 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 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 WES with the following coverage metrics|
|Mean sequencing depth at exome level||143X|
|Nucleotides with >20x sequencing coverage (%)||99.86%|
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.
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.