This is a presentation on "Calcium Channelopathies".
My name is David Friel from
the Department of Neurosciences at Case Western Reserve University.
My research focuses on calcium and electrical signaling
in excitable cells and the impact of
calcium channel mutations on
electrophysiological properties of cells involved in cerebellar motor control.
In this presentation, we'll start by defining what we mean by channelopathies and present
a conceptual framework for discussing them that
is based on the central dogma of molecular biology.
We will then discuss classification of channelopathies based on
clinical syndrome and based on the ion channels that are defective.
This will be followed by a discussion of voltage-gated calcium channel,
which will be the focus of our discussion of calcium channelopathies.
We will then present several examples of
human calcium channelopathies that span the range of
phenotypic complexity and illustrate
general concepts that are relevant to other channelopathies.
This will be followed by a summary of the main points in the presentation.
Let's start by defining what we mean by channelopathies.
Channelopathies are diseases that result from defects in ion channel function.
Channelopathies can be classified based on whether they are inherited or acquired.
But for our purposes,
it will be more useful to classify them based on whether they
result from genetic versus non genetic causes.
Genetic causes involve modification of genes that encode channel proteins,
which either occur in germ cells and can be passed on to
offspring or in somatic cells as a result of de novo mutations.
Non-genetic causes include actions of drugs or
toxins or autoimmune attack of ion channels.
While the focus of this presentation will be on
channelopathies that result from modification of channel genes,
two examples of channel disorders that result from non-genetic causes
are cardiac arrhythmias such as long QT syndrome,
which can result as a side effect of
some pharmacological agents used to treat other disorders that alter
the activity of ion channels important for
normal cardiac function. And Lambert-Eaton myasthenic syndrome,
an autoimmune disease characterized by lots of
presynaptic calcium channels at the neuromuscular junction leading to muscle weakness.