Genetics, an alternative way to discover, characterize and understand ion channels

Migraine: an endemic disease inside the blood–brain barrier

Migraine is a complex neurological disorder that in recent years has received more and more attention. Knowledge regarding this primary headache has increased substantially, both with respect to its pathogenesis and how to effectively treat its symptoms. Over the years, the proposed location of the onset of migraine has moved from the periphery of the nervous system toward deeper parts of the brain. Migraine can be viewed as an inherited failure of trigeminal sensory processing with abnormal neuronal excitability in the trigeminal nucleus caudalis, which, in turn, causes central sensitization and amplification of the pain. Increased activation of the trigeminal nerve during a migraine attack causes release of the calcitonin gene-related peptide (CGRP) inside and outside the BBB. Within the CNS, CGRP promotes trigeminal sensory input and facilitates central sensitization. The future introduction of CGRP antagonists in clinical practice could represent significant progress for acute migraine therapy.

Epilepsy genetics

BACKGROUND

Epilepsy genetics is a complex and rapidly expanding field that involves the contributions and collaborative efforts of geneticists, molecular biologists, epidemiologists, and clinicians.

REVIEW SUMMARY

This article first provides a background review of basic terminology and contributions from the fields of epilepsy, genetics, and genetic epidemiology. It further describes the evidence for the genetic basis of epilepsy and enumerates the linkage findings and epilepsy susceptibility genes reported to date. It then addresses existing knowledge about the genetics of electroencephalogram abnormalities and their relationship to clinical epilepsy. Finally, it gives guidelines for genetic counseling, with attention to patients' frequently asked questions.

CONCLUSIONS

This review provides a framework for understanding current and future investigations in the field of epilepsy genetics and a way to assist and educate individuals and families living with epilepsy.

A mutation (V260M) in the middle of the M2 pore-lining domain of the glycine receptor causes hereditary hyperekplexia

We investigated the molecular basis of hyperekplexia (STHE), an inherited neurological disorder characterised by neonatal hypertonia and an exaggerated startle response, in a kindred and identified a novel missense mutation in the pore-lining M2 domain of the alpha1 subunit of the glycine receptor (GLRA1). Sequencing analysis of all exons of the GLRA1 gene revealed a G1158A base transition in affected, heterozygous patients. The base transition results in a valine to methionine substitution at codon 260 in the middle of the M2 transmembrane domain. The location within the M2 domain suggests for this substitution a likely role in altering ion channel properties.