Whole exome sequencing is performed on genomic DNA using the Agilent SureSelect Clinical Research Exome v3 targeted sequence capture method to enrich for the exome. Direct sequencing of the amplified captured regions was performed using 2X150bp reads on Illumina next generation sequencing (NGS) systems. A base is considered to have sufficient coverage at 20X and an exon is considered fully covered if all coding bases plus three nucleotides of flanking sequence on either side are covered at 20X or more. A list of low coverage regions, if any, is available upon request. Alignment to the human reference genome (hg19) is performed and annotated variants are identified in the targeted region. Variants reviewed have a minimum coverage of 8X and an alternate allele frequency of 20% or higher. Indels and single nucleotide variants (SNVs) may be confirmed by Sanger sequence analysis before reporting at director discretion. Mitochondrial DNA is sequenced and analyzed using the same pipeline. Mitochondrial variants are reported at a minimum of 5% heteroplasmy if the average coverage of the mitochondrial genome is 1000x. This assay cannot detect variants in regions of the exome that are not covered, such as deep intronic, promoter, and enhancer regions, and areas containing large numbers of tandem repeats. Genes and/or exons located in pseudogene regions are not covered in this assay. Copy number variation (CNV) analysis is designed to detect deletions and duplications of three exons or more; in some instances, due to the size of the exons or other factors, not all CNVs may be analyzed. This assay does not interrogate CNVs in mitochondrial DNA. CNV analysis will not detect tandem repeats, balanced alterations (reciprocal translocations, Robertsonian translocations, inversions, and balanced insertions), methylation abnormalities, triploidy, and genomic imbalances in segmentally duplicated regions. This assay is not designed to detect mosaicism; possible cases of mosaicism may be investigated at the discretion of the laboratory director. Primary data analysis is performed using Illumina bcl2fastq converter v2.19. Secondary analysis is performed using Illumina DRAGEN Bio-IT Platform v.3.4.12. Tertiary data analysis is performed using SnpEff v4.3t and PerkinElmer’s internal ODIN v.1.01 software. CNV and absence of heterozygosity are assessed using BioDiscovery’s NxClinical v5.1 software.
StepOne® biochemical test is performed using tandem mass spectrometry as well as other technologies are used for biochemical profiling.
The CNGnome® Test is performed using direct sequencing of genomic DNA was performed using 2X150bp reads on Illumina next generation sequencing (NGS) systems at a mean coverage of 5X in the target region. Alignment to the human reference genome (hg19) was performed and copy number variant (CNV) calls made using the NxClinical software v5.0 (BioDiscovery, Inc., El Segundo, CA). CNVs meeting internal quality assessment guidelines are confirmed by real time quantitative PCR (qPCR) for records after results are reported. Some CNVs are confirmed by qPCR before reporting at a director’s discretion. This assay cannot detect CNVs in regions of the genome that are not amenable to NGS and does not interrogate CNVs in mitochondrial DNA. This assay will not detect tandem repeats, balanced alterations (reciprocal translocations, Robertsonian translocations, inversions, and balanced insertions), point mutations, methylation abnormalities, genomic imbalances in segmentally duplicated regions and mosaicism; possible cases of mosaicism may be investigated at the discretion of the laboratory director. Small pathogenic CNVs within the exon, some small intragenic deletions or duplications, as well as complex rearrangements may not be detected. This assay has been validated to detect copy number variants >25 Kb and also has the ability to detect copy number changes such as homozygous deletions. For targeted CNV testing, smaller CNVs may be interrogated, analyzed, and reported per director discretion. This assay may not be able to discern between CNVs that are high copy number gains such as, duplication >=4X. CNVs involving genes with pseudogenes and pseudoexons may not be reliable detected or reported. Due to high similarity of certain regions on chromosome X and chromosome Y, CNVs in the following regions may not be detected for male patients (chrX: 60000-2699520; chrX:154930289-155260560; chrY:10000-2649520; chrY: :59033286-59363566).