Clinical genetics is a branch of medicine that specialises in genetic disorders, and
it's designed to help people who have or who are at risk of a genetic disorder. One in
seventeen people will be affected by a genetic disorder and although individually they are
very rare, collectively genetic disorders are common, and there are 7000 different types,
so it requires someone with specialist knowledge of clinical genetics to be able to help people
in that situation. My job is to take into consideration lots of different elements about
a person's risk for a genetic disorder, namely their family history and their early health
and development profile, and to see if piecing all those aspects together can help me come
to a diagnostic shortlist and provide them with the most appropriate tests to allow a
diagnosis to be reached accurately and as quickly as possible.
As a geneticist I help patients of all different ages, primarily I am a paediatrician and I
specialise in genetic disorders that affect children, but genetics applies to people from
cradle to grave and before that and beyond, so I help all sorts of different people. Principally
in paediatric genetics, I see children who may have a number of different problems - perhaps
they're not growing properly, perhaps they look different to other family members, their
development is not as it should be for a child their age, and my job is to bring together
all the different elements of that condition and see if I can come up with a genetic diagnosis
by implementing the most appropriate test for that child, so that could be a chromosome
test or it could be a single gene test, or increasingly available to us now in our genetics
toolbox is next generation sequencing where we can undertake genetic testing of hundreds
or thousands of genes and tailor the analysis to a patient's individual requirements based
on their clinical history to come up with a diagnosis that is appropriate for them.
Clinical genetics is a fast-moving specialty, that is benefitting from an evolution in genetic
testing. In recent times we have improved our ability to test chromosomes, this test
having gone from being a microscope-based analysis to a much higher throughput test
using DNA-based molecular technology. Similarly, in genetic testing, we have moved from a platform
where we needed to analyse genes on an individual basis gene by gene, and therefore requiring
us to be able to identify which of the 20,000 genes to start with, to the tests being a
much higher throughput test so that we can analyse thousands of genes in one go. This
still requires us to use our expert knowledge to be able to interpret the results on an
individual basis bespoke to a patient's particular situation.
I recently saw a three-and-a-half year old boy who was brought to see me by his mother.
This boy was not yet walking or talking, and he also had a number of medical problems as
well. As such, he had seen lots of different doctors and lots of different specialists
to try and explain on an individual basis all these different problems, but nobody had
the opportunity to think about all of these problems in one. Having taken a history from
the mother and explored the family history and drawn a pedigree, having examined the
child, I was able to then suggest some further tests which then came up with a diagnosis
for the child. Having had his genetic condition explained, I was then able to offer advice
on follow-up management for that child, but also to provide genetic counselling for the
more extended family to ensure that their chance of having a child with similar issues
was reduced.