Related Experiment Video
Updated: Aug 19, 2026

Detection of Copy Number Alterations Using Single Cell Sequencing
Published on: February 17, 2017
Inverse correlation between SMN1 and SMN2 copy numbers: evidence for gene conversion from SMN2 to SMN1
Shuji Ogino1, Sizhen Gao, Debra G B Leonard
1Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115, USA. sogino@partners.org
Abstract:
Most carriers of autosomal recessive spinal muscular atrophy (SMA) have only one copy of SMN1 because of SMN1 gene deletions or gene conversions from SMN1 to SMN2, which has only one base difference in coding sequence from SMN1. Using SMN gene dosage analysis, we determined the copy numbers of SMN1 and SMN2 in the general population as well as in SMA patients and carriers. Increased SMN1 copy number is associated with decreased SMN2 copy number in the general population; that is, SMN2 copy number was decreased to one or zero copies in 11 of 13 individuals with three or four copies of SMN1, whereas only 71 of 164 individuals with two copies of SMN1 had one or zero copies of SMN2 (P<0.01). SMN2 copy number was increased to three or four in a subset of SMN1 deletion/conversion carriers, and in most SMA patients with a milder phenotype. In conclusion, our data provide evidence that gene conversion from SMN2 to SMN1 occurs, and that SMN1 converted from SMN2 is present in the general population.
More Related Videos
07:02Evaluation of Exon Inclusion Induced by Splice Switching Antisense Oligonucleotides in SMA Patient Fibroblasts
Published on: May 11, 2018
09:16Investigation of the Transcriptional Role of a RUNX1 Intronic Silencer by CRISPR/Cas9 Ribonucleoprotein in Acute Myeloid Leukemia Cells
Published on: September 1, 2019
Related Concept Videos
Gene Conversion
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
Genome Copying Errors
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Comparing Copy Number Variations and SNPs
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Gene Conversion