Is BICD2 p.Leu121Val (c.361C>G) pathogenic?

BICD2 p.Leu121Val (c.361C>G) is classified Uncertain significance in BICD2 (ClinVar, Single submitter, 1 submitter). AlphaMissense: likely benign (0.1909); Absent from gnomAD v4.1; Associated with autosomal dominant childhood-onset proximal spinal muscular atrophy with contractures.

What condition is associated with BICD2 p.Leu121Val (c.361C>G)?

BICD2 p.Leu121Val (c.361C>G) is associated with autosomal dominant childhood-onset proximal spinal muscular atrophy with contractures, spinal muscular atrophy, lower extremity-predominant, 2b, prenatal onset, autosomal dominant (ClinVar).

How common is BICD2 p.Leu121Val (c.361C>G) in the general population?

BICD2 p.Leu121Val (c.361C>G) is absent from gnomAD v4.1 (gnomAD).

What do computational predictors say about BICD2 p.Leu121Val (c.361C>G)?

AlphaMissense predicts likely benign (score 0.1909) — an in-silico prediction, not a clinical call.

BICD2 p.Leu121Val

Q: How is Autosomal dominant childhood-onset proximal spinal muscular atrophy inherited?

Typically Autosomal dominant (Orphanet). A genetic counselor can assess individual risk for a family.

c.361C>G · VCV3381915

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.1909 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

0/2 damaging

AlphaMissense, SaProt · REVEL no call

Conditions

autosomal dominant childhood-onset proximal spinal muscular atrophy with contractures

Computational evidence

Protein change
AlphaMissense	0.1909	likely benign
REVEL	0.317	indeterminate
SaProt	LLR -9.23	tolerated
⇒ AlphaMissense and SaProt both call this tolerated; REVEL makes no call.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 8.6	GERP 2.7, phastCons 1
Regional constraint	o/e 0.79	unconstrained · MANE · 42 kb · p 0.00095 · regional, not allelic
Overall
CADD	26.9	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — a triage signal, not a reclassification

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: BICD2
Protein: p.Leu121Val
Coding: c.361C>G
MANE Select: NM_001003800
Type: single nucleotide variant
Location: chr9:92729116 (GRCh38)
Gene constraint: LOEUF 0.507 · pLI 0.95 (gnomAD)
Structure: AlphaFold pLDDT 78.89 · 2 PDB
Residue 121: the 'interacts with dynll1, dync1h1, dync1i2, dctn1 and dctn2' region

Full BICD2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

autosomal dominant childhood-onset proximal spinal muscular atrophy with contractures — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: spinal muscular atrophy, lower extremity-predominant, 2b, prenatal onset, autosomal dominant

For Autosomal dominant childhood-onset proximal spinal muscular atrophy (Orphanet):

Inheritance: Autosomal dominant
Onset: Adolescent, Antenatal, Childhood, Infancy, Neonatal
Prevalence: <1 / 1 000 000 (Worldwide)

Similar variants

BICD2 p.Leu121= Likely benign ★ same residue
BICD2 p.Arg694Cys Pathogenic/Likely pathogenic ★★ same condition
BICD2 p.Arg694Gly Pathogenic/Likely pathogenic ★★ same condition
BICD2 p.Arg694His Pathogenic/Likely pathogenic ★★ same condition
BICD2 p.Glu774Lys Pathogenic/Likely pathogenic ★★ same condition
BICD2 p.Lys734Glu Likely pathogenic ★★ same condition
BICD2 p.Ser107Leu Pathogenic ★★ ⚠ same condition
BICD2 p.Thr703Met Pathogenic/Likely pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/bicd2-p-leu121val (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown