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Sequencing Ventures into the Unknown of Rare Disease

Linda Seaton
| Jun 20, 2013

hope for rare diseasesAfter the birth of your child, you realize something is wrong with them. After numerous visits to physicians and specialists, and rounds of tests, you still don’t have an answer. All they can tell you is “Yes, there’s something wrong. We don’t know the cause and we don’t know how to treat it.”

As a mother, I can’t imagine what this must feel like. Yet, the parents of more than 300 million children worldwide experience this day after day. Their children have a rare disease, defined as a disorder affecting fewer than 200,000 people. Often they feel alone as they navigate a diagnostic odyssey to find out what’s wrong with their child. That’s where organizations such as the Global Genes Project can help. The non-profit, patient advocacy organization collaborates with a network of about 45,000 individuals and different rare disease organizations, increasing awareness of these diseases and providing families with a sense of community. 

In the midst of all the unknowns, one thing that is understood about the more than 7,000 rare diseases is that most have genetic causes. This makes next-generation sequencing (NGS) a valuable tool for diagnosis, offering some hope for patients and their families. Recently, NGS was used to identify a rare mitochondrial disease afflicting two sisters of a California family. Cristy and Rick Spooner had been on a 14-year diagnostic odyssey, first with Cali and then with Ryann, in an attempt to find out why the girls suffered from seizures and developmental delays. The answer finally came when whole-exome sequencing was performed on the girl’s blood samples. For the Spooners, the diagnosis has been life-changing. “Our huge question mark exploded into tiny pieces and has been replaced by a name—Complex I deficiency. The great news is that there is a treatment available, a program of vitamins and an eating regimen that might help their development.” 

Here’s hoping that NGS will provide answers to more families of children with rare diseases.