# NM_007078.3(LDB3):c.609G>A (p.Ser203=)

https://sugi.bio/variant/ldb3-p-ser203

## Summary

**LDB3 p.Ser203= (c.609G>A)** is classified **Benign** in LDB3 (ClinVar, Multiple submitters, 12 submitters; last evaluated 2026-02-02). Common (popmax 5.12%, afr) — too common for a highly-penetrant pathogenic allele; Associated with Cardiovascular phenotype.

**At a glance:** Benign · review: Multiple submitters · rsID rs45531131 · 12 submitters · 3 linked conditions · common (popmax 5.12%, afr) — too common for a highly-penetrant pathogenic allele

## For patients & families {#patients}

This is a change in the LDB3 gene that is classified as benign — not considered disease-causing, submitted by 12 submitters, and is linked to Cardiovascular phenotype.

*Reference information, not medical advice, and not a prediction for any individual. A genetic counselor or clinician can interpret what it means for you and your family.*

**Support & next steps:** [Find a genetic counselor (NSGC)](https://findageneticcounselor.nsgc.org/).

## Identity {#identity}

| Field | Value |
| --- | --- |
| Gene | [LDB3](https://sugi.bio/atlas/gene/LDB3/) |
| Protein change (HGVS p.) | p.Ser203= |
| Coding change (HGVS c.) | c.609G>A |
| MANE Select transcript | [NM_007078](https://www.ncbi.nlm.nih.gov/nuccore/NM_007078) |
| dbSNP | [rs45531131](https://www.ncbi.nlm.nih.gov/snp/rs45531131/) |
| Variant type | single nucleotide variant |
| Location | chr10:86681723-86681723 (GRCh38) |
| ClinVar | [VCV45550](https://www.ncbi.nlm.nih.gov/clinvar/variation/45550/) |

**All HGVS expressions:** `LRG_385:g.18160G>A`, `LRG_385t1:c.609G>A`, `LRG_385t2:c.321+1566G>A`, `NC_000010.10:g.88441480G>A`, `NC_000010.11:g.86681723G>A`, `NG_008876.1:g.18160G>A`, `NM_001080114.2:c.321+1566G>A`, `NM_001080115.2:c.609G>A`, `NM_001080116.1:c.321+1566G>A`, `NM_001171610.2:c.609G>A`, `NM_001171611.2:c.609G>A`, `NM_001368063.1:c.609G>A`, `NM_001368064.1:c.609G>A`, `NM_001368065.1:c.609G>A`, `NM_001368066.1:c.321+1566G>A`, `NM_001368067.1:c.321+1566G>A`, `NM_001368068.1:c.321+1566G>A`, `NM_007078.3:c.609G>A`

## Computational & population evidence {#evidence}

**Concordance:** Evidence sources **disagree** — common (popmax 5.12%, afr) — too common for a highly-penetrant pathogenic allele.

- **Missense predictors (AlphaMissense/REVEL/SaProt) do not apply** to this variant type — they score amino-acid substitutions only. For non-missense variants the computational signal comes from conservation and, for splice-region changes, SpliceAI (below), not from a missing predictor score.
- SpliceAI predicts **acceptor gain** (Δ 0.24) — a splice-altering prediction the current classification does not reflect
- Conservation: phyloP -4.429, GERP -4.14 — fast-evolving / accelerated position
- CADD: **PHRED 12.07**. No single ClinGen-calibrated threshold exists and the expert panels that use CADD disagree — GUCY2D/AIPL1 require ≥ 20.0 for an untranslated-region variant, ABCA4 ≥ 28.1 for a synonymous or indel variant, the Pulmonary Hypertension panel imports Pejaver 2022's missense-calibrated numbers, and the Antibody Deficiencies panel declines CADD entirely for PIK3CD. CADD v1.7 also incorporates Zoonomia phyloP, so it partly re-expresses the conservation above. *Descriptive; no threshold applied.*
- SpliceAI deltas (raw): acceptor loss **0.13**, donor loss **0.00**, acceptor gain **0.24**, donor gain **0.00**. Largest is acceptor gain.
- SpliceAI deltas (masked): acceptor loss **0.00**, donor loss **0.00**, acceptor gain **0.24**, donor gain **0.00**.
- Population frequency (gnomAD v4.1): grpmax **5.12%** (afr) · FAF95 4.98% · FAF99 4.93% · 3,838/74,962 in the highest group · 4,397/1,611,658 alleles overall — common (popmax 5.12%, afr) — too common for a highly-penetrant pathogenic allele.

| Ancestry group | Allele frequency | 1 in |
| --- | --- | --- |
| African / African-American (grpmax) | 5.12% | 20 |
| Remaining individuals (not grpmax-eligible) | 0.326% | 307 |
| Admixed American | 0.236% | 424 |
| Middle Eastern | 0.149% | 673 |
| European (non-Finnish) | 0.0169% | 5,923 |
| South Asian | 0.0066% | 15,150 |
| Finnish (not grpmax-eligible) | 0.00157% | 63,620 |

*Computational predictors are not independent (ClinGen Variant Classification guidance): AlphaMissense (Cheng et al. 2023) carries the ACMG weight for missense and conservation (phyloP/GERP/phastCons) for non-missense; REVEL (Pejaver-2022 calibrated strength bands) and SaProt (Su et al. 2023, structure-aware, ClinVar-independent protein language model, raw LLR) are shown as orthogonal agreement signals, not additive. For frequency, the gnomAD v4.1 grpmax filtering allele frequency (FAF95) is ClinGen's designated BA1/BS1 input (gnomAD v4 guidance v3.0, June 2025); BA1/BS1 thresholds are disease-specific, not a blanket 5%. Predictions, not a clinical determination.*

## Gene constraint & dosage {#gene-context}

**LDB3** population constraint: LOEUF 0.864, pLI 1.5098e-11, missense-Z 0.90565. *Lower LOEUF and higher pLI indicate a gene that tolerates loss-of-function poorly; ClinGen dosage is the curated haploinsufficiency call.*

Curated gene–disease validity (ClinGen):

- **hypertrophic cardiomyopathy** — Disputed (AD)
- **dilated cardiomyopathy 1C** — Limited (AD)
- **arrhythmogenic right ventricular cardiomyopathy** — Disputed (AD)
- **cardiomyopathy, dilated, 2l** — Strong (AR)

## Protein context {#protein}


AlphaFold model confidence (whole protein): pLDDT 61.98, 22% of residues very-high.

**2 experimental structure(s)** (PDB): [1RGW](https://www.rcsb.org/structure/1RGW), [4YDP](https://www.rcsb.org/structure/4YDP).

## What this gene does {#gene-function}

*Describes the biological roles of LDB3 (the gene this variant disrupts) — not effects measured for this specific variant. A damaging variant is expected to affect these functions and pathways; the degree depends on the variant.*

**How this variant is thought to act:** LDB3's established molecular role includes cytoskeletal protein binding.


### Molecular function & processes (GO — experimentally supported) {#go}

**Molecular function:** cytoskeletal protein binding.

## Clinical significance {#significance}

**Benign** — review status Multiple submitters *(criteria provided, multiple submitters, no conflicts)*, last evaluated 2026-02-02.

**Submitter consensus:** conflicting (11 Benign, 1 Likely benign).

**Submission history:** 12 submissions (2008–2026); classifications have differed over time.

### Submitter classifications {#submitters}

| Submitter | Classification | Review | Method | Date |
| --- | --- | --- | --- | --- |
| ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories | Benign | criteria provided, single submitter | clinical testing | 2025-05-20 |
| Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+ | Benign | no assertion criteria provided | clinical testing |  |
| Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center | Benign | no assertion criteria provided | clinical testing |  |
| Breakthrough Genomics, Breakthrough Genomics | Benign | criteria provided, single submitter | not provided |  |
| CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario | Benign | criteria provided, single submitter | clinical testing | 2016-04-11 |
| Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine | Benign | criteria provided, single submitter | clinical testing | 2008-06-10 |
| GeneDx | Benign | criteria provided, single submitter | clinical testing | 2015-03-03 |
| Clinical Genetics, Academic Medical Center | Benign | no assertion criteria provided | clinical testing |  |
| Genome Diagnostics Laboratory, University Medical Center Utrecht | Benign | no assertion criteria provided | clinical testing |  |
| Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC) | Likely benign | no assertion criteria provided | clinical testing |  |
| Ambry Genetics | Benign | criteria provided, single submitter | clinical testing | 2015-09-09 |
| Labcorp Genetics (formerly Invitae), Labcorp | Benign | criteria provided, single submitter | clinical testing | 2026-02-02 |

## Associated conditions {#conditions}

[Cardiovascular phenotype](https://sugi.bio/atlas/disease/cardiovascular-phenotype/), [cardiomyopathy](https://sugi.bio/atlas/disease/cardiomyopathy/), [myofibrillar myopathy 4](https://sugi.bio/atlas/disease/myofibrillar-myopathy-4/).

**Reported phenotype names (ClinVar):** Cardiovascular phenotype, not specified, Myofibrillar myopathy 4, Cardiomyopathy, not provided, AllHighlyPenetrant, none provided, Cardiomyopathies, Zaspopathy (type).

## Similar variants {#similar}

Related LDB3 variant pages (same residue, condition, or type): [LDB3 p.Ser203Leu](/variant/ldb3-p-ser203leu), [LDB3 p.Ser203Trp](/variant/ldb3-p-ser203trp), [LDB3 p.Ala147Thr](/variant/ldb3-p-ala147thr), [LDB3 p.Ala165Val](/variant/ldb3-p-ala165val), [LDB3 c.1231+4A>C](/variant/ldb3-c-1231-plus-4a-c), [LDB3 c.1858-11C>A](/variant/ldb3-c-1858-minus-11c-a), [LDB3 c.246-3C>T](/variant/ldb3-c-246-minus-3c-t), [LDB3 c.322-1G>A](/variant/ldb3-c-322-minus-1g-a).

### Data sources & attribution {#sources}

ClinVar (NCBI — public domain, built 2026-10-14); gnomAD v4.1 (Broad Institute, built 2026-10-14); AlphaMissense (Cheng et al. 2023, © Google DeepMind — CC BY 4.0, built 2026-01-27); REVEL (Ioannidis et al. 2016 — ODbL, built 2026-07-13); SaProt (Su et al. 2023 — MIT, built 2026-10-14); SpliceAI (Illumina — free for non-commercial use, built 2026-10-13); CADD (Rentzsch et al. 2019, University of Washington — free for non-commercial use, built 2026-10-10); Conservation (phyloP/phastCons/GERP) (UCSC hg38 470-way mammal (Hiller Lab) + Ensembl Compara, built 2026-07-12); gnomAD Non-coding Constraint (Gnocchi) (Chen et al. 2024, Broad Institute — CC0, built 2026-10-11); gnomAD Regional Missense Constraint (Broad Institute — CC0, built 2026-10-13); Pangolin (Zeng & Li 2022 — CC BY 4.0, built 2026-10-11); Repeat regions (UCSC — RepeatMasker, TRF, segmental duplications, built 2026-10-11); ClinGen (ClinGen, built 2026-09-22); UniProt (CC BY 4.0); Reactome / GO (CC BY 4.0, built 2026-09-23); MaveDB (per-record license, built 2026-10-11); CIViC (CC0, built 2026-09-22); Orphanet (Orphanet, built 2026-06-12)

*Primary record: NCBI ClinVar (variation 45550). Classifications reflect these databases as of the page's build date and may change. Free reference use — not medical advice; consult the primary submitters and a clinician.*