Affiliations: Neurogenetics Laboratory, Department of Medicine, King
Fahad National Guard Hospital, Riyadh, Saudi Arabia | Division of Cardiovascular Surgery, Mayo Clinic,
Rochester, MI, USA
Note: [] Correspondence: Mohammed Al Jumah, M.D., Department of Medicine,
Medical and Health Sciences Research Center, King Saud bin Abdulaziz University
for Health Sciences, National Guard Health Affairs, P.O. Box 22490, Riyadh
11426, Saudi Arabia. Tel.: +966 1 252 0088, Ext. 13509; Fax: +966 1 252 0772;
E-mail: jumahm@ngha.med.sa
Abstract: 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.
Keywords: Spinal muscular atrophy, carrier screening, gene deletion, Saudi population
