Survival of motor neuron 2 (SMN2) is a gene that encodes the SMN protein (full and truncated) in humans.^[5][6]

Quick Facts SMN2, Available structures ...

SMN2
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1G5V, 1MHN, 2LEH, 3S6N, 4A4E, 4A4G, 4GLI, 4NL6, 4NL7, 4QQ6
Identifiers
Aliases	SMN2, BCD541, C-BCD541, GEMIN1, SMNC, TDRD16B, survival of motor neuron 2, centromeric, survival motor neuron 2, centromeric
External IDs	OMIM: 601627; MGI: 109257; HomoloGene: 292; GeneCards: SMN2; OMA:SMN2 - orthologs
Gene location (Human) Chr. Chromosome 5 (human)[1] Band 5q13.2 Start 70,049,638 bp[1] End 70,078,522 bp[1]
Gene location (Mouse) Chr. Chromosome 13 (mouse)[2] Band 13 D1|13 52.99 cM Start 100,261,360 bp[2] End 100,274,198 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in epithelium of colon endometrium smooth muscle tissue right uterine tube olfactory zone of nasal mucosa rectum bone marrow tonsil muscle of thigh Descending thoracic aorta Top expressed in yolk sac morula secondary oocyte somite maxillary prominence neural tube ganglionic eminence medial ganglionic eminence thymus lip More reference expression data BioGPS n/a
Gene ontology Molecular function protein binding RNA binding identical protein binding Cellular component cytoplasm SMN-Sm protein complex cytosol Cajal body nucleoplasm SMN complex Z disc neuron projection cytoplasmic ribonucleoprotein granule nucleus gemini of coiled bodies perikaryon cell projection Biological process DNA-templated transcription, termination mRNA processing nervous system development spliceosomal snRNP assembly spliceosomal complex assembly RNA splicing import into nucleus Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 6607 20595 Ensembl ENSG00000277773 ENSG00000205571 ENSG00000273772 ENSMUSG00000021645 UniProt Q16637 P97801 RefSeq (mRNA) NM_017411 NM_022875 NM_022876 NM_022877 NM_001252629 NM_011420 RefSeq (protein) NP_059107 NP_075013 NP_075014 NP_075015 NP_000335 NP_001284644 NP_075012 NP_001239558 NP_035550 Location (UCSC) Chr 5: 70.05 – 70.08 Mb Chr 13: 100.26 – 100.27 Mb PubMed search [3] [4]
Wikidata
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The SMN2 gene is part of a 500 kb inverted duplication on chromosome 5q13. This duplicated region contains at least four genes and repetitive elements which make it prone to rearrangements and deletions. The repetitiveness and complexity of the sequence have also caused difficulty in determining the organization of this genomic region. The telomeric (SMN1) and centromeric (SMN2) copies of this gene are nearly identical and encode the same protein. The critical sequence difference between the two genes is a single nucleotide in exon 7, which is thought to be an exon splice enhancer. The nucleotide substitution in SMN2 results in around 80-90% of its transcripts to be a truncated, unstable protein of no biological function (Δ7SMN) and only 10-20% of its transcripts being full-length protein (fl-SMN).^{[citation needed]}

Note that the nine exons of both the telomeric and centromeric copies are designated historically as exon 1, 2a, 2b, and 3–8. It is thought that gene conversion events may involve the two genes, leading to varying copy numbers of each gene.^[6]

While mutations in the telomeric copy are associated with spinal muscular atrophy, mutations in this gene, the centromeric copy, do not lead to disease. This gene may be a modifier of disease caused by mutation in the telomeric copy.^{[citation needed]}