A Pilot Study Of Spinal Muscular Atrophy Carrier Screening In Saudi Arabia

Spinal muscular atrophy (SMA), an autosomal recessive inherited disease, is a leading genetic killer under the age of two years. This disease is caused by mutation in the telomeric copy of the survival motor neuron gene (SMN1). Most carriers of SMA have one chromosome 5 with a normal SMN1 gene and one with a deleted SMN1 gene. Although no large-scale population-based studies has been done in Saudi Arabia, previous estimations have indicated that incidence of SMA is much higher in Saudi population compared with other ethnic groups, partly because of high prevalence of consanguineous marriages. In this pilot study, we used a highly sensitive quantitative-polymerase chain reaction method to detect SMA carriers. Among 187 normal individuals not related to an SMA patient the carrier frequency was 5%, i.e. one carrier in each 20 persons compared to one in 50-80 in other parts of the world. Based on the results of this pilot study a new project is designed to further analyze the carrier status of SMA in Saudi population. This will shed more light on the magnitude of the problem of SMA in the countries with high rate of consanguinity.