Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 32009
The Contribution of the PCR-Enzymatic Digestion in the Positive Diagnosis of Proximal Spinal Muscular Atrophy in the Moroccan Population

Authors: H. Merhni, A. Sbiti, I. Ratbi, A. Sefiani


The proximal spinal muscular atrophy (SMA) is a group of neuromuscular disorders characterized by progressive muscle weakness due to the degeneration and loss of anterior motor neurons of the spinal cord. Depending on the age of onset of symptoms and their evolution, four types of SMA, varying in severity, result in a mutations of the SMN gene (survival of Motor neuron). We have analyzed the DNA of 295 patients referred to our genetic counseling; since January 1996 until October 2014; for suspected SMA. The homozygous deletion of exon 7 of the SMN gene was found in 133 patients; of which, 40.6% were born to consanguineous parents. In countries like Morocco, where the frequency of heterozygotes for SMA is high, genetic testing should be offered as first-line and, after careful clinical assessment, especially in newborns and infants with congenital hypotonia unexplained and prognosis compromise. The molecular diagnosis of SMA allows a quick and certainly diagnosis, provide adequate genetic counseling for families at risk and suggest, for couples who want prenatal diagnosis. The analysis of the SMN gene is a perfect example of genetic testing with an excellent cost/benefit ratio that can be of great interest in public health, especially in low-income countries. We emphasize in this work for the benefit of the generalization of molecular diagnosis of SMA by the technique of PCR-enzymatic digestion in other centers in Morocco.

Keywords: Exon7, PCR-digestion, SMA, SMN gene.

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 831


[1] Fang et al. BMC Musculoskeletal Disorders (2015) 16:11
[2] E.L. Arkblad et al. / Neuromuscular Disorders 16 (2006) 830–838
[3] Lefebvre S, Burglen L, Reboullet S et al :Identification and characterization of a spinal muscular atrophy-determining gene. Cell1995; 80 : 155-165
[4] Balraj Mittal, Rapid molecular diagnosis of spinal muscular atrophy Indian J Med Res. 2012 January; 135(1): 6–8.
[5] Panigrahi I, Kesari A, Phadke S R, Mittal B. Clinical and molecular diagnosis of spinal muscular atrophy. Neurol India 2002;50:117
[6] Scheffer H, Cobben JH, Matthijis G et al : Best practice guidelines for molecular analysis in spinal muscular atrophy, Euro J Hum Genet 2001; 9 : 484-491.
[7] ZERRES K., RUDNIK-SCHÖNEBORN S.: « Spinal muscular atrophies ». In: « Emery and Rimoin’s principales and practice of medical genetics », 3e édition, 1996, 2(113) : 2387- 2403
[8] Cherkaoui M, Baali A, larrouy G, et al. (2005) Consanguinity, fertility of couples and mortality of children in the high Atlas population (commons of Anougal and Azgour, Marrakesh, Morocco). Int J Anthropol 20:199–206/ Jaouad IC, Elalaoui SC, Sbiti A, et al. Consanguineous marriages in Morocco and the consequence for the incidence of auto-somal recessive disorders. J Biosoc Sci 2009;5: 575–81.
[9] Jaber Lyahyai, Aziza Sbiti, Amina Barakat, Ilham Ratbi, and Abdelaziz Sefiani « Spinal Muscular Atrophy Carrier Frequency and Estimated Prevalence of the Disease in Moroccan Newborns » Genetic Testing And Molecular Biomarkers Volume XX, Number XX, 2011 ª Mary Ann Liebert, Inc.Pp. 1–4 DOI: 10.1089/gtmb.2011.0149
[10] Hendrickson, B.C., Donohoe, C., Akmaev, V.R., et al. Differences in SMN1 allele frequencies among ethnic groups within North America, J. Med. Genet., 2009, vol. 46, pp. 641–644.
[11] Seoyoung Yoon, Chang Hoon Lee, Kyung_A Lee, Determination of SMN1 and SMN2 copy numbers in a Korean population using multiplex ligation_dependent probe amplification, Korean J. Lab. Med., 2010, vol. 30, pp. 93–96.
[12] Zhu Sheng Yuan, Fu Xiong, Ya_Jun Chen, et al., Molecular characterization of SMN copy number derived from carrier screening and from core families with SMA in a Chinese population, Eur. J. Hum. Genet., 2010, vol. 18, pp. 978–984.
[13] Bueno, K.C., Gouveaa, S.P., Genaria, A.B., et al., Detection of spinal muscular atrophy carriers in a sam ple of the Brazilian population, Neuroepidemiology, 2011, vol. 36, pp. 105_108.
[14] Thieme A, Mitulla B, Schulze F, et al. (1994) Chronic childhood spinal muscular atrophy in Germany (West-Thuringen)—an epidemiological study. Hum Genet 93:344–346.
[15] O. Soloviov, N. Hryschenko, and L. Livshits Spinal Muscular Atrophy Carrier Frequency in ukraine1 Russian Journal of Genetics Vol. 49 No. 9 2013
[16] Hasanzad, M., Azad, M., Kahrizi, K., et al., Carrier frequency of SMA by quantitative analysis of the SMN1 deletion in the Iranian population, Eur. J. Neurol., 2010, vol. 17 P, pp. 160–162.
[17] Imen Rekik, Amir Boukhris, Sourour Ketata, Mohamed Amri, Nourhene Essid, Imed Feki, and Chokri MhiriAnn Indian Acad Neurol. 2013 Jan-Mar; 16(1): 57–61
[18] Neurol India. 2012 May-Jun; 60(3):294-8. doi: 10.4103/0028-3886.98514.Spinal muscular atrophy: clinical spectrum and genetic mutations in Pakistani children.Ibrahim S1, Moatter T
[19] AnPediatr(Barc). 2015Mar;82(3):15965doi:10.1016/j.anpedi.2014.06.021Epub 2014 Aug 4.Infantile spinal atrophy: our experience in the last 25 years).(Article in Spanish) Madrid Rodríguez A1, Martínez Martínez PL2, Ramos Fernández JM2, Urda Cardona A2, Martínez Antón J2.
[20] Madrid Rodríguez A1, Martínez Martínez PL2, Ramos Fernández JM2, Urda Cardona A2, Martínez Antón J2. (Infantile spinal atrophy: our experience in the last 25 years). 2015 Mar; 82(3):159-65. doi: 10.1016/j.anpedi.2014.06.021. Epub 2014 Aug 4.
[21] BratislLekListy. 2007;108(3):1337.MolecularanalysisofSMN1andNAIPgenenEgyptianpatientswithspinalmuscularatrophy.Essawi ML1, EffatLK, ShanabGM, Al-Ettribi GM, El-HaronuiAA, Karim AM.
[22] Al-Rajeh S, Bademosi O, Gascon GG, Stumpf D. Werdnig Hoffman's disease (spinal muscular atrophy type I): A clinical study of 25 Saudi nationals in Al-Khobar. Ann Saudi Med. 1992 Jan; 12(1):67-71.
[23] Ibrahim S, Moatter T, Saleem AF. Spinal muscular atrophy: clinical spectrum and genetic mutations in Pakistani children. Neurol India. 2012 May-Jun; 60(3):294-8. doi: 10.4103/0028-3886.98514.
[24] Salahshourifar I, Shafeghati Y, Golkar Z, Najmabadi H. Molecular analysis of the neuronal apoptosis inhibitory protein gene in families with spinal muscular atrophy. Arch Iran Med. 2007 Oct; 10(4):509-13.
[25] Clinical and genetic study of spinal muscular atrophies in Oman. Koul R, Al Futaisi A, Chacko A, Rao V, Simsek M, Muralitharan S, Ganguly SS, Bayoumi R. Journal of Child Neurology / Vol. 22, No. 10, October 2007
[26] Shawky RM, Abd el-Aleem K, Rifaat MM, Moustafa A. Molecular diagnosis of spinal muscular atrophy in Egyptians. East Mediterr Health J. 2001 Jan-Mar; 7(1-2):229-37.