Interestingly, in three couples who had an SMA child, both the parents had two SMN1 copies. Families of this type have not been previously reported. Our results emphasize the importance of performing a detailed carrier study in SMA parents with two SMN1 copies. Expanding the analysis to other ...
Mutations in the survival motor neuron gene ( SMN1 ) are determinant for the development of the disease whereas the number of copies of SMN2, the highly homologous copy of SMN1, plays a role as a phenotypic modifier factor. The detection of SMN1 homozygous deletions is the typical test for ...
Muscle MRI of the pelvis (p), thighs (q), and legs (r) and muscle biopsy (s and t) of a 16 years old male patient with molecularly confirmed Spinal Muscular Atrophy with homozygous deletion of the exons 7 and 8 of the SMN1 gene, with the SMN2 gene presenting 4 copies of the ...
Most heterozygous SMA carriers have only one SMN1 copy in one of the alleles (1/0 carriers). However, a few carriers lack SMN1 in one of their chromosomes, but present two gene copies in the other. These "2/0 carriers" are undistinguishable from non-carrier individuals (1/1) with ...