Analyzing the exome—focusing your NGS analysis with high performance target capture
The document discusses exome sequencing and compares the performance of the xGen Exome Research Panel to other commercial exome sequencing panels. Key points:
1) An independent study directly compared the xGen panel to 3 other commercial exome panels and found that the xGen panel had a higher on-target rate and more uniform coverage than the other panels.
2) When deeply sequenced, the xGen panel was able to achieve greater than 20x coverage of over 94% of bases in the RefSeq database with only 40 million reads, which is 2.5-4 times fewer reads than the other panels tested.
3) The coverage profile produced by the xGen panel more closely resembled whole genome sequencing
Outline
• Review
– Exomesequencing
– xGen® product portfolio
– Library preparation and target enrichment
• Exome performance
– Multiplexed capture
– Deep sequencing
– Exome sequencing vs. WGS
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3.
Exome sequencing
• Affordableapproach to interrogate protein
coding portion of the genome and identify
disease-causing variants
• Mendelian disorders
– Prenatal diagnosis, preimplementation
genetic diagnosis, carrier/mutation detection
of heterogeneous disorders (e.g., hearing
loss), prognosis of preclinical individuals
• Personalized cancer therapy
– Diagnosis and prognosis, treatment,
discovery of new cancer-related genes,
address tumor heterogeneity and evolution
[http://www.dnalinkus.com/us/service/exome_sequencing.html]
xGen Lockdown Probesare individually synthesized
and quality controlled
Each xGen Lockdown Probe receives an individual ESI-MS analysis
Failed Remade
Full length
Truncated
Full length
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Inventoried xGen targetcapture panels
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Panel No. of genes Target capture size (Mb) No. of probes
Exome 19,396 51.0 429,826
AML 264 1.4 11,743
Pan-Cancer 127 0.8 7,816
Human ID 0.03 229
Human mtDNA 0.02 138
Outline
• Review
– Exomesequencing
– xGen® product portfolio
– Library preparation and target enrichment
• Exome performance
– Multiplexed capture
– Deep sequencing
– Exome sequencing vs. WGS
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Comparative study design
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1.An independent large genome center
compared 4 exome capture panels
2. 12 libraries were made with KAPA
Hyper Prep kit
3. Libraries were split into each capture
4. Captures were completed by each
vendor’s protocol
5. Captures were sequenced on a lane of
the HiSeq® 2500 instrument in high
output mode and subsampled to 17M
PE reads or 5.1 Gb of sequencing
First exons areGC rich
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Kalari, K.R. et al. (2006) First exons and introns - a survey of GC content and gene structure in the human genome.
In Silico Biology, 6(3):237-242
Outline
• Review
– Exomesequencing
– xGen® product portfolio
– Library preparation and target enrichment
• Exome performance
– Multiplexed capture
– Deep sequencing
– Exome sequencing vs. WGS
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22.
Exome deep sequencing
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1.1 library made with KAPA Hyper
Prep kit
2. Each library was sequenced on
a lane of the HiSeq 4000
instrument
3. Sequencing was subsampled to
matched reads
xGen Exome ResearchPanel
• Exhibits superior uniformity
• Yields the most complete coverage of RefSeq database
• The only commercial exome panel without reduced first exon
coverage
• Achieves ≥20X coverage of >94% of bases in RefSeq database with
only 40M reads, ~2.5 – 4X fewer than any other exome panel tested
• Coverage profile resembles whole genome data
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