title: Repeat expansion in C9ORF72 is not a major cause of amyotrophic lateral sclerosis among Iranian patients.
abstract: Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease in populations of European descent. It was recently found that a hexanucleotide repeat expansion in C9ORF72 is its most common cause in these populations. The contribution of C9ORF72 to ALS is notably lower in the Far East, but its role in other populations is unknown. Results of C9ORF72 screening in 78 unrelated Iranian ALS patients are reported here. The repeat expansion was observed in only 1 (5.9%) of the familial and 1 (1.6%) of the sporadic cases. These figures are to be compared, respectively, with 30% and 6.9% among patients of European ethnicity. Screenings of C9ORF72 in other Middle East countries will reveal whether the low contribution of C9ORF72 to ALS is a feature of the entire region. During the screenings, it was noted that in a single family, 3 individuals affected with ALS, Parkinson's disease, or frontotemporal dementia all carried the repeat expansion. The finding suggests the mutation does rarely contribute to the etiology of Parkinson's disease.
authors: School of Biology, College of Science, University of Tehran, Tehran, Iran.
authors: Afagh
authors: A
authors: Alavi
authors: Shahriar
authors: S
authors: Nafissi
authors: Mohammad
authors: M
authors: Rohani
authors: Gholamali
authors: G
authors: Shahidi
authors: Babak
authors: B
authors: Zamani
authors: Hosein
authors: H
authors: Shamshiri
authors: Iman
authors: I
authors: Safari
authors: Elahe
authors: E
authors: Elahi
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D001284:Atrophy; D000073885:C9orf72 Protein; D002540:Cerebral Cortex / Q000473:pathology; D042622:DNA Repeat Expansion; D005060:Europe / Q000208:ethnology; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011506:Proteins / Q000235:genetics*; D055815:Young Adult
chemical_list: D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; D011506:Proteins
keywords: ALS; Amyotrophic lateral sclerosis; C9ORF72 expansions; Parkinson's disease