Table of Contents
Journal of Neurodegenerative Diseases
Volume 2013 (2013), Article ID 903875, 7 pages
http://dx.doi.org/10.1155/2013/903875
Clinical Study

Clinical and Genetic Study of Algerian Patients with Spinal Muscular Atrophy

1Service of Neurology CHU of Constantine, Algeria
2Laboratory of Biology and Molecular Genetics CHU and University of Constantine, Algeria
3Laboratory of Biochemistry CHU of Constantine, Algeria
4Service of Pediatrics CHU de Constantine, Algeria
5Genetic Department of the Necker Hospital and Paris Descartes University, Paris, France

Received 20 December 2012; Revised 12 February 2013; Accepted 18 February 2013

Academic Editor: Haluk Topaloglu

Copyright © 2013 Y. Sifi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Spinal muscular atrophy (SMA) is the second most common lethal autosomal recessive disorder. It is divided into the acute Werdnig-Hoffmann disease (type I), the intermediate form (type II), the Kugelberg-Welander disease (type III), and the adult form (type IV). The gene involved in all four forms of SMA, the so-called survival motor neuron (SMN) gene, is duplicated, with a telomeric (tel SMN or SMN1) and a centromeric copy (cent SMN or SMN2). SMN1 is homozygously deleted in over 95% of SMA patients. Another candidate gene in SMA is the neuronal apoptosis inhibitory protein (NAIP) gene; it shows homozygous deletions in 45–67% of type I and 20–42% of type II/type III patients. Here we studied the SMN and NAIP genes in 92 Algerian SMA patients (20 type I, 16 type II, 53 type III, and 3 type IV) from 57 unrelated families, using a semiquantitative PCR approach. Homozygous deletions of SMN1 exons 7 and/or 8 were found in 75% of the families. Deletions of exon 4 and/or 5 of the NAIP gene were found in around 25%. Conversely, the quantitative analysis of SMN2 copies showed a significant correlation between SMN2 copy number and the type of SMA.