A primary goal of the Chromosome 18 Clinical Research Center is to link genes to traits (or in genetics-speak: "genotype to phenotype"). In other words, we want to understand what happens when a piece of chromosome 18 is deleted or duplicated. How does it impact a person's health? What does it mean for their development? We spend a lot of time thinking about and trying to understand the impact of missing pieces of chromosome 18.
However, did you know that we can also learn a great deal from what ISN'T missing? The Chromosome 18 Clinical Research Center has enrolled over 300 people with 18q-, each with their own unique breakpoint. These breakpoints are located all along the chromosome, meaning that there are a wide ranges of deletions. Yet, there are two areas on chromosome 18 that have never been reported missing in a person with 18q-. They are located right next to the chromosome 18 centromere and within the 18q21.1 band, which is about in the middle of the chromosome 18 long arm
Since we have seen people with deletions of every other part of the chromosome, we suspect that there is a reason that deletions of these regions have never been seen. These genes are so critical that pregnancies missing one of the two copies of these genes cannot be carried to term. We call these regions "hemizygous lethal". We hypothesize that there are one or more genes in each of these regions that are absolutely critical to early development. This is information that is of significance to the wider community of biological scientists.
While this information does not give us specific information about people with chromosome 18 conditions, it does show how research carried out by the Research Center contributes to our general understanding of developmental biology. It is a great example of how families can have an impact even beyond the world of chromosome 18, just by participating in research!
