SMN2
Chr 5ARsurvival of motor neuron 2, centromeric
Also known as: BCD541, C-BCD541, GEMIN1, SMNC, TDRD16B
The SMN2 protein localizes to nuclear gems and forms complexes involved in small ribonucleoprotein biogenesis. Mutations in SMN2 serve as a modifier of spinal muscular atrophy type III, following an autosomal recessive inheritance pattern. Unlike its nearly identical telomeric copy SMN1, mutations in the centromeric SMN2 gene do not directly cause disease but can influence disease severity through gene conversion events and copy number variation.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Mild missense constraint
The highest-scoring mechanism for this gene is dominant-negative.
Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
SMN2 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
A Study Evaluating the Effectiveness and Safety of Risdiplam Administered as an Early Intervention in Pediatric Participants With Spinal Muscular Atrophy After Gene Therapy
RECRUITINGLong-term Follow-up of Patients With Spinal Muscular Atrophy Treated With OAV101 in Clinical Trials
RECRUITINGA Study to Evaluate How Apitegromab Works in Subjects Who Are Less Than 2 Years Old and Have Spinal Muscular Atrophy
RECRUITINGLong Read Analysis in Spinal Muscular Atrophy - LOREASI
RECRUITINGA Study to Learn About Salanersen's (BIIB115) Effects on Movement and Its Safety in Participants Aged 15 to 60 Years With Spinal Muscular Atrophy (SMA) Who Are Either New to SMA Treatment or Were Previously Treated With Risdiplam
RECRUITINGSpinal Muscular Atrophy Neonatal Screening Program
RECRUITINGA Study to Learn About Salanersen's (BIIB115) Effects on Movement and Its Safety When Given Before Symptoms Appear in Babies With Genetically Diagnosed Spinal Muscular Atrophy (SMA)
RECRUITINGA Study of Risdiplam in Infants With Genetically Diagnosed and Presymptomatic Spinal Muscular Atrophy
ACTIVE NOT RECRUITINGStudy of Safety, Tolerability and Efficacy of GB221 in Infants With Spinal Muscular Atrophy Type 1
RECRUITINGA Study to Learn About the Safety and Effects of Salanersen (BIIB115) When Given to Babies With Spinal Muscular Atrophy (SMA) Who Were Previously Treated With Onasemnogene Abeparvovec
NOT YET RECRUITINGA Study Evaluating the Effectiveness and Safety of Risdiplam Administered in Pediatric Patients With Spinal Muscular Atrophy Who Experienced a Plateau or Decline in Function After Gene Therapy
RECRUITINGExternal Resources
Links to major genomics databases and tools