SSBP1

Chr 7AD

single stranded DNA binding protein 1

Also known as: Mt-SSB, OPA13, SOSS-B1, SSBP, mtSSB

NCBI Gene: 6742ENSG00000106028UniProt: Q04837

SSBP1 is a housekeeping gene involved in mitochondrial biogenesis (Tiranti et al., 1995 [PubMed 7789991]). It is also a subunit of a single-stranded DNA (ssDNA)-binding complex involved in the maintenance of genome stability (Huang et al., 2009) [PubMed 19683501].[supplied by OMIM, Feb 2010]

Primary Disease Associations & Inheritance

Optic atrophy 13 with retinal and foveal abnormalitiesMIM #165510
AD
74
ClinVar variants
50
Pathogenic / LP
0.00
pLI score
2
Active trials
Clinical Summary— SSBP1
🧬
Gene-Disease Validity (ClinGen)
optic atrophy 13 with retinal and foveal abnormalities · ADStrong

Strong evidence — appropriate for clinical testing

2 total gene-disease associations curated

⚡
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
50 Pathogenic / Likely Pathogenic· 21 VUS of 74 total submissions
💊
Clinical Trials
2 active or recruiting trials — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD
Tolerant — LoF & missense variants common in population
LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.
0.90LOEUF
pLI 0.004
Z-score 1.82
OE 0.46 (0.25–0.90)
Tolerant

Typical tolerance to LoF variation

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.
1.11Z-score
OE missense 0.66 (0.53–0.83)
56 obs / 84.7 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.
LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.46 (0.25–0.90)
0≤0.351.4
Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.66 (0.53–0.83)
0≤0.61.4
Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.1.10
0≤1.21.6
LoF obs/exp: 6 / 13.1Missense obs/exp: 56 / 84.7Syn Z: -0.39

ClinVar Variant Classifications

74 submitted variants in ClinVar

ClinVar

Classification Summary

Pathogenic48
Likely Pathogenic2
VUS21
Likely Benign3
48
Pathogenic
2
Likely Pathogenic
21
VUS
3
Likely Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
3
45
0
48
Likely Pathogenic
0
1
1
0
2
VUS
1
15
5
0
21
Likely Benign
0
2
1
0
3
Benign
0
0
0
0
0
Total12152074

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

SSBP1 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

OMIM — Genotype-Phenotype Relationships

1 OMIM entry

OMIM

Optic atrophy 13 with retinal and foveal abnormalities

MIM #165510

Molecular basis of disorder known

Autosomal dominant
Clinical Literature
Landmark / reviewRecent case evidence
Key Publications
Landmark & review papers · by relevance
PubMed
Syndromic retinitis pigmentosa.
Karuntu JS et al.·Prog Retin Eye Res
2025Review
Autophagy deficiency abolishes liver mitochondrial DNA segregation.
Tostes K et al.·Autophagy
2022
Integrated analysis of single-cell RNA-seq and spatial transcriptomics to identify the lactylation-related protein TUBB2A as a potential biomarker for glioblastoma in cancer cells by machine learning.
Xu Y et al.·Front Immunol
2025
SSBP1-Disease Update: Expanding the Genetic and Clinical Spectrum, Reporting Variable Penetrance and Confirming Recessive Inheritance.
Jurkute N et al.·Invest Ophthalmol Vis Sci
2021
Consequences of compromised mitochondrial genome integrity.
Gustafson MA et al.·DNA Repair (Amst)
2020Review
Inhibiting SSBP1 enhances ferroptosis and improves the effectiveness of sorafenib treatment for liver cancer.
Li S et al.·Int J Oncol
2025
Maternal mosaicism in SSBP1 causing optic atrophy with retinal degeneration: implications for genetic counseling.
Chang YH et al.·Orphanet J Rare Dis
2023Case report
The importance of genome sequencing: unraveling SSBP1 variant missed by exome sequencing.
Jun JW et al.·Ophthalmic Genet
2023Case report
SSBP1 mutations cause mtDNA depletion underlying a complex optic atrophy disorder.
Del Dotto V et al.·J Clin Invest
2020
Characterization of SSBP1-related optic atrophy and foveopathy.
Meunier I et al.·Sci Rep
2021
Top 10 resultsSearch PubMed ↗
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC
Top 5 resultsSearch Europe PMC ↗

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

ClinicalTrials.gov
Solid TumorAdvanced Solid TumorMetastatic Cancer

KPMNG Study of MOlecular Profiling Guided Therapy Based on Genomic Alterations in Advanced Solid Tumors II

RECRUITING
NCT05525858Seoul National University Bundang HospitalStarted 2022-09-28
AlectinibAtezolizumabErlotinib
Lymphoma, Non-HodgkinMultiple MyelomaAdvanced Solid Tumors

TAPUR: Testing the Use of Food and Drug Administration (FDA) Approved Drugs That Target a Specific Abnormality in a Tumor Gene in People With Advanced Stage Cancer

RECRUITING
NCT02693535Phase PHASE2American Society of Clinical OncologyStarted 2016-03-14
PalbociclibSunitinibTemsirolimus

External Resources

Links to major genomics databases and tools