2023 ACMG Annual Clinical Genetics Meeting Digital Edition: Poster Gallery-Improving DNA sequencing from dried blood spots for multi-tiered newborn screening

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This document discusses the development of a sequential sequencing approach for second-tier testing of dried blood spots (DBS) in newborn screening (NBS) for inborn metabolic disorders. NBS is a crucial public health practice that allows for early diagnosis and treatment of infants with genetic conditions. The study aimed to demonstrate the feasibility of using DNA sequencing to confirm or reject primary screening results and improve the accuracy of NBS.<br /><br />The approach involved extracting high molecular weight DNA from a single DBS punch and performing multiplex gene sequencing of 72 genes associated with metabolic disorders. Long-read genome sequencing was also employed to confirm pathogenic variants identified by the gene panel and determine their cis/trans phase. The study utilized the PacBio Sequel II system for ultra-low input preparation and sequence analysis.<br /><br />The results showed that the sequencing approach had high sensitivity and positive predictive value for detecting single nucleotide variants (SNVs) compared to standard HiFi sequencing. However, the sensitivity for detecting small insertions or deletions (indels) was slightly reduced. The study also successfully confirmed pathogenic variants in the cystic fibrosis transmembrane conductance regulator (CFTR) gene using long-read sequencing.<br /><br />Overall, the sequential sequencing approach demonstrated the potential to improve the accuracy of NBS by reducing false positive results and providing molecular results for most cases. It also enabled haplotype phasing of single-nucleotide and indel variants without the need for parental testing. The study suggests that combining metabolic testing with DNA sequencing has the potential to enhance NBS and facilitate early diagnosis and intervention for infants with genetic disorders.

Asset Subtitle

Presenting Author - Neeru Gandotra, MS, PhD, MB(ASCP); Co-Author - Gang Peng, PhD; Co-Author - Irina Tikhonova, PhD; Co-Author - Caroline Storer, PhD; Co-Author - Justin Mak, BS; Co-Author - Guilin Wang, PhD; Co-Author - Tina M. Cowan, PhD; Co-Author - Curt Scharfe, MD, PhD;

Meta Tag

Biochemical genetics

Exome sequencing

Genome sequencing

Genomic Methodologies

Metabolic Disorder

NextGen Sequencing

Variant Detection

Co-Author Gang Peng, PhD

Co-Author Irina Tikhonova, PhD

Co-Author Caroline Storer, PhD

Co-Author Justin Mak, BS

Co-Author Guilin Wang, PhD

Co-Author Tina M. Cowan, PhD

Co-Author Curt Scharfe, MD, PhD

Presenting Author Neeru Gandotra, MS, PhD, MB(ASCP)

Keywords

sequential sequencing approach

second-tier testing

dried blood spots

newborn screening

inborn metabolic disorders

DNA sequencing

gene panel

PacBio Sequel II system

single nucleotide variants

indels