Carrier frequency of SMA by quantitative analysis of the SMN1 deletion in the Northern- Cyprus population

Abstract

Abstract SMA is a rare autosomal recessive neuromuscular, where one out of each 10,000 live births can be affected by this syndrome. The atrophy is caused by the gradual loss of alpha motor neurons, within the ventral spinal cord or motor nuclei within the lower brainstem. In this study, we aimed to evaluate the carrier frequency of SMN1 gene mutation causing SMA in Turkish Cypriot population. This is the first study to evaluate the SMN1 deletion mutations in this population. The mutation detection of SMN1 gene mutations, Exon 7 and 8 deletions, and c.849C/T substitution within exon 7 was carried out according to the manufacturer. In the total of 100 individuals, 3 patients turned out to be a carrier of the SMN1 gene in both exon 7 and 8 (carrier number 1) and another patient (Carrier number 2) showed a carrier status of SMN1 gene only in exon 7. Our findings revealed that the carrier frequency of mutation in the SMN1 gene for exon 7 is 4% (4:100 healthy individuals) while its mutation prevalence for exon 8 is 3% (3:100 healthy individuals). In conclusion, health precautions must be taken due to the high frequency of SMA linked to the deletion of the SMN1 gene. Carrier testing as a technique for genetic counseling may be advantageous for individuals with a positive family history. To this population, we strongly recommend prenatal testing. The Ministry of Health has received our findings, and they will decide whether to include tests for the SMN1 gene variant in premarital examinations.