Newborn Genetic Diagnosis—Guinness World Record

In 2003, the Human Genome Project claimed completion of the first DNA sequence of “the” human genome. Just fifteen years later, hospitals can sequence an entire baby’s genome literally overnight. Typically 19 hours, at the Rady Children’s Institute for Genomic Medicine, holder of the Guinness World Record, up there with the world’s largest origami rhinoceros and the most balloons popped by a dog.

Why is it important to sequence the DNA of a newborn? 
4%, that is 1 in 25 newborn children has a genetic defect. Think about it—How many people you know have this in themselves or their families?

For treatment, the first days, even hours, are crucial. The sooner therapy can start, the greater the chance that an infant can have a normal life. This is true for certain conditions, such as phenylketonuria (PKU), cystic fibrosis, immune deficiencies, and tendencies for early cancer. PKI has always had a simple biochemical test, required by law at birth. But what of thousands of other conditions? Sadly, many of those still have no cure. But increasingly, knowing the defect early means help is on the way.

To sequence a genome and get useful information that fast requires chip technology and enormous computing power.

First, there is Illumina DNA sequencing, in which fragments of DNA are stuck to special “start” sequences at either end of the double strand. A DNA polymerase enzyme extends each strand, by fitting nucleotides to its complement. Eventually, all the short sequences are read and assembled into a whole genome.

Next, a computational pipeline that screens the three million base pairs and sifts out the likely errors that might have significance. Surprisingly, the fast majority of mutations have no effect at all on our health; even some “lethal” ones, whose compensatory mechanism may be unknown. Each of us has about 150 mutations not present in our parents. So, finding the lethal one may be quite a trick.

Studies show that genome sequencing can actually save money, as well as lives, by enabling treatment before a condition does irreparable damage.
So in the future, should we screen all newborns for entire genomes at birth, not just PKU?

That is another question, with many complex considerations.