RT Journal Article SR Electronic T1 New VAPB deletion variant and exclusion of VAPB mutations in familial ALS JF Neurology JO Neurology FD Lippincott Williams & Wilkins SP 1179 OP 1185 DO 10.1212/01.wnl.0000289760.85237.4e VO 70 IS 14 A1 Landers, J. E. A1 Leclerc, A. L. A1 Shi, L. A1 Virkud, A. A1 Cho, T. A1 Maxwell, M. M. A1 Henry, A. F. A1 Polak, M. A1 Glass, J. D. A1 Kwiatkowski, T. J. A1 Al-Chalabi, A. A1 Shaw, C. E. A1 Leigh, P. N. A1 Rodriguez-Leyza, I. A1 McKenna-Yasek, D. A1 Sapp, P. C. A1 Brown, R. H. YR 2008 UL http://n.neurology.org/content/70/14/1179.abstract AB Objective: Amyotrophic lateral sclerosis (ALS) is a progressive, neurodegenerative disorder involving upper and lower motor neurons. The vesicle-associated membrane protein B (VAPB) gene has been genetically linked to ALS in several large Brazilian families in which the disorder is caused by a proline to serine mutation at codon 56 (P56S). No additional mutations have been identified. Methods: To establish the prevalence of VAPB mutations, we screened 80 familial ALS samples by DNA sequencing. Results: Our study failed to identify any novel VAPB gene mutations but identified a single Brazilian family harboring the P56S mutation. In a second familial ALS case, we identified a three–base pair deletion within exon 5 of the VAPB gene that deleted the serine residue at position 160 (ΔS160). This variant is detected in a normal population at low frequency (0.45%). Analyses of homology alignment and secondary structure predict that this deletion significantly alters the structure of VAPB, although a GFP-ΔS160 VAPB fusion protein demonstrates a wild-type subcellular localization. This contrasts the aberrant localization observed in a GFP-P56S VAPB fusion protein. The allele frequency of ΔS160 in patients with sporadic ALS does not differ significantly from that in the normal population. Conclusions: Mutations in the VAPB gene are rare and the ΔS160 variant does not contribute to the development of amyotrophic lateral sclerosis. ALS=amyotrophic lateral sclerosis; ER=endoplasmic reticulum; FALS=familial ALS; SALS=sporadic ALS; VAPB=vesicle-associated membrane protein B.