Referenced in: none

Automatically associated channels: Cav2.1

Title: Downbeat positioning nystagmus is a common clinical feature despite variable phenotypes in an FHM1 family.

Authors: Ichiro Yabe, Mayumi Kitagawa, Yashio Suzuki, Keishi Fujiwara, Takahito Wada, Takashi Tsubuku, Norihito Takeichi, Ken Sakushima, Hiroyuki Soma, Sachiko Tsuji, Masaaki Niino, Shinji Saitoh, Hidenao Sasaki

Journal, date & volume: J. Neurol., 2008 Oct , 255, 1541-4

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/18670797

Abstract
Clinical examinations and mutational analyses were carried out in three patients of a Japanese familial hemiplegic migraine (FHM) pedigree. Each affected member demonstrated a broad clinical spectrum that included hemiplegic migraine with progressive cerebellar ataxia, migraine without aura, and episodic ataxia. Despite this variability, all members exhibited marked downbeat positioning nystagmus, and magnetic resonance images (MRI) all showed cerebellar atrophy predominantly of the cerebellar vermis. All affected members had a T666M missense mutation in the protein encoded by the CACNA1A gene (calcium channel, voltage-dependent, P/Q type, alpha 1A subunit). Although clinical features associated with the T666M CACNA1A mutation are highly variable, downbeat positioning nystagmus may be an important clinical feature of this disease.