title: Molecular Genetic Analysis of Survival Motor Neuron Gene in 460 Turkish Cases with Suspicious Spinal Muscular Atrophy Disease.
abstract: OBJECTIVE
  To describe 12 yr experience of molecular genetic diagnosis of Spinal Muscular Atrophy (SMA) in 460 cases of Turkish patients.
  
  
  METHODS
  A retrospective analysis was performed on data from 460 cases, referred to Medical Genetics Laboratory, Ege University's Hospital, Izmir, Turkey, prediagnosed as SMA or with family history of SMA between 2003 and 2014. The PCR-restriction fragment length polymorphism (RFLP) and the Multiplex ligation-dependent probe amplification (MLPA) analysis were performed to detect the survival motor neuron (SMN)1 deletions and to estimate SMN1 and SMN2 gene copy numbers.
  
  
  RESULTS
  Using PCR-RFLP test, 159 of 324 postnatal and 18 of 77 prenatal cases were detected to have SMN1 deletions. From positive samples, 88.13% had a homozygous deletion in both exon 7 and exon 8 of SMN1. Using MLPA, 54.5% of families revealed heterozygous deletions of SMN1, and 2 or 3 copies of SMN2, suggesting a healthy SMA carrier. Among patients referred for SMA testing, the annual percentage of patients diagnosed as SMA has decreased gradually from 90.62% (2003) down to 20.83% (2014).
  
  
  CONCLUSIONS
  Although PCR-RFLP method is a reliable test for SMA screening, MLPA is a necessary additional test and provide relevant data for genetic counseling of families having previously affected child. The gradual decrease in the percentage of patients molecularly diagnosed as SMA shows that clinicians have begun to use genetic tests in the differential diagnosis of muscular atrophies. Cost and availability of these genetic tests has greatly attributed to their use.
authors.affiliation: 1.Young Researchers and Elites Club, North Tehran Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Afrooz
authors.initials: A
authors.lastname: Rashnonejad
authors.affiliation: Department of Medical Genetics, Faculty of Medicine, Ege University, Izmir, Turkey.
authors.forename: Huseyin
authors.initials: H
authors.lastname: Onay
authors.affiliation: Department of Pediatrics, Faculty of medicine, Ege University, Izmir, Turkey.
authors.forename: Tahir
authors.initials: T
authors.lastname: Atik
authors.affiliation: Department of molecular biology and biochemistry, health Sciences Institute, Acibadem University, Istanbul, Tureky.
authors.forename: Ozlem
authors.initials: O
authors.lastname: Atan Sahin
authors.affiliation: Division of Child Neurology, Department of Pediatrics, faculty of medicine, Ege University, Izmir, Turkey.
authors.forename: Sarenur
authors.initials: S
authors.lastname: Gokben
authors.affiliation: Division of Child Neurology, Department of Pediatrics, faculty of medicine, Ege University, Izmir, Turkey.
authors.forename: Hasan
authors.initials: H
authors.lastname: Tekgul
authors.affiliation: Department of Medical Genetics, Faculty of Medicine, Ege University, Izmir, Turkey; Department of Pediatrics, Faculty of medicine, Ege University, Izmir, Turkey.
authors.forename: Ferda
authors.initials: F
authors.lastname: Ozkinay
keywords: MLPA; Retrospective; SMA; SMN1