RT Journal Article
SR Electronic
T1 The c.859G&gt;C variant in the <em>SMN2</em> gene is associated with types II and III SMA and originates from a common ancestor
JF Journal of Medical Genetics
JO J Med Genet
FD BMJ Publishing Group Ltd
SP 640
OP 642
DO 10.1136/jmg.2010.079004
VO 47
IS 9
A1 Bernal, S
A1 Alías, L
A1 Barceló, M J
A1 Also-Rallo, E
A1 Martínez-Hernández, R
A1 Gámez, J
A1 Guillén-Navarro, E
A1 Rosell, J
A1 Hernando, I
A1 Rodríguez-Alvarez, F J
A1 Borrego, S
A1 Millán, J M
A1 Hernández-Chico, C
A1 Baiget, M
A1 Fuentes-Prior, P
A1 Tizzano, E F
YR 2010
UL http://jmg.bmj.com/content/47/9/640.abstract
AB Homozygous mutations of the telomeric SMN1 gene lead to degeneration of motor neurons causing spinal muscular atrophy (SMA). A highly similar centromeric gene (SMN2) can only partially compensate for SMN1 deficiency. The c.859G&gt;C variant in SMN2 has been recently reported as a positive disease modifier. We identified the variant in 10 unrelated chronic SMA patients with a wide spectrum of phenotypes ranging from type II patients who can only sit to adult walkers. Haplotype analysis strongly suggests that the variant originated from a common ancestor. Our results confirm that the c.859G&gt;C variant is a milder SMN2 allele and predict a direct correlation between SMN activity and phenotypic severity.