Since some fetal and newborn diseases cannot be detected by “an appropriate biochemical test” (The Scientist), genome sequencing has become a new form of technology used to analyze issues with DNA, such as mutations which lead to severe disease.
Scientists have specifically experimented with exome sequencing, which, according to a study on Science Direct from last year, “focuses on targeted sequencing of the protein coding regions of the genomic DNA and shows promise as a new tool in gene discovery for complex diseases.” According to Science Daily, a study published by UC San Francisco from earlier this month used exome sequencing “to identify genetic diseases as the underlying cause in 37 of 127 cases of nonimmune hydros fetalis (NIHF), a life-threatening condition in which the fetus is overloaded with fluid.” Additionally, UCSF discovered that, out of all the diagnoses of NIHF, “exome sequencing….[helped] find a genetic diagnosis in nearly 30 percent of cases of previously unknown cause.” With exome sequencing being extremely precise in pinpointing single mutations, the mutations were identified as originating from “the fetus, but several were inherited, with the potential to affect future pregnancies with the same biologic mother or father.”
There was another study conducted by UC San Francisco, UC Berkeley, and Tata Consultancy Services to “analyze the blood spots taken at birth for rare disorders” missed by “older screening technology, tandem mass spectrometry (MS/MS),” and ”they found that….sequencing can still be useful in cases that look suspicious but were not clearly identified by MS/MS.” With exam sequencing, they worked to identify “mutations in 78 genes that are known to be involved in the 48 metabolic disorders for which every California newborn is screens.” What was different about sequencing from other older technology was that they used “dried blood spots, which are taken at birth and then stored, could be used to analyze DNA.” While there were “shortcoming of the sequencing approach” with issues such as misdiagnosis, scientists ultimately concluded that, “in cases where MS/MS showed something might be wrong, but doctors were unsure of what it was…..sequencing may yet prove useful in identifying newborns with treatable conditions that current screening methods cannot find.”
The technology of exome sequencing is still fairly new. But, it is far more conclusive than standard technology, such as MS/MS, which has less definitive results. Scientists are still working to perfect exome sequencing, but pinpointing specific mutations will help define symptoms that newborns and fetuses express and discover genetic diseases.
References
“Exome Sequencing.” Exome Sequencing - an Overview | ScienceDirect Topics,
sequencing.
“Genomic Sequencing as a Standalone Newborn Screening Tool Falls Short, But May Help
Diagnose Uncertain Cases.” Genomic Sequencing as a Standalone Newborn Screening Tool
Falls Short, But May Help Diagnose Uncertain Cases | UC San Francisco, 22 Oct. 2020,
screening-tool-falls-short-may-help.
Olena, Abby. “Babies' Genomes Identify Risks Overlooked by Newborn Screens.” The Scientist
overlooked-by-newborn-screens-65282.
Article written by Keya Mann
Article edited by Lucy Ge
Graphics by Karis Kelly
Group advised by Sadia Akbar