Summary of Canadian Discovery of the FHS Gene

Dr. Kym Boycott’s lab in Ontario, Canada recently discovered “SRCAP” as the gene which causes Floating Harbor Syndrome (FHS), a condition characterized by short stature, delayed bone age, speech delay and distinct facial features.  While we are still learning a lot about SRCAP and its role in the body, Dr. Boycott’s team found that mutations which cause FHS are clustered in on specific part (exon 34) of the SRCAP gene.  This suggests that this is a very important part of the gene for its function.  While everyone has two copies of the SRCAP gene- one inherited from their mother and one inherited from their father- individuals with FHS have a change or “mutation” on one of their copies of SRCAP, making it unable to work properly.  Having a mutation in one copy of the SRCAP leads to the features seen in individuals with FHS.  To date, all SRCAP mutations reported have been “de novo” or “of the new.”  This terms refers to the fact that the mutations were not seen in the parents of the individual with FHS, and therefore, the gene mutation was not inherited from a parent.  Instead, de novo mutations occur spontaneously, or by chance, at the time of conception of the individual with FHS.  These SRCAP mutations are not caused by environmental insults (what parents ate, or did) but rather just happen by chance.  Because of this, it is very unlikely that parents of a child with FHS will have another child with FHS.  However, when individuals with FHS have children, because they already carry the SRCAP mutation, they have a 50% or 1 in 2 chance of having a child who also has with FHS.  There are genetic testing options to test pregnancies to see if they carry a FHS mutation. 

So what does this discovery mean?  It means that now families with a suspected FHS diagnosis can have a genetic test to confirm the diagnosis of FHS.  It also means that we can better define FHS and over time will be able to better describe that the life of a person with FHS may be like.