Clinical and Genetic Study of Algerian Patients with Spinal Muscular Atrophy.

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.

SUBMITTER: Sifi Y 

PROVIDER: S-EPMC4437343 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature