MID1

Chr XXLR

midline 1

Also known as: BBBG1, FXY, GBBB, GBBB1, MIDIN, OGS1, OS, OSX

NCBI Gene: 4281ENSG00000101871UniProt: O15344OMIM: 300552

This protein is an E3 ubiquitin ligase that forms homodimers associated with microtubules and regulates protein phosphatase PP2A through ubiquitination of IGBP1. Mutations cause X-linked Opitz GBBB syndrome, characterized by midline developmental abnormalities including cleft lip, laryngeal cleft, congenital heart defects, hypospadias, and agenesis of the corpus callosum. The gene is highly constrained against loss-of-function variants and follows X-linked recessive inheritance.

OMIMResearchSummary from RefSeq, OMIM, UniProt
LOFmechanismXLRLOEUF 0.301 OMIM phenotype
Clinical Summary— MID1
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Gene-Disease Validity (ClinGen)
X-linked Opitz G/BBB syndrome · XLDefinitive

Definitive — sufficient evidence for diagnostic panels

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Population Constraint (gnomAD)
Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 0.98). One damaged copy is likely sufficient to cause disease.
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Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD
LoF intolerant — likely haploinsufficient
LoF Constraint
0.30LOEUF
pLI 0.980
Z-score 3.81
OE 0.10 (0.04–0.30)
Highly constrained

Highly LoF-intolerant (top ~10% of genes)

Missense Constraint
2.92Z-score
OE missense 0.52 (0.45–0.59)
152 obs / 292.6 exp
Mild constraint

Moderately missense-constrained (top ~2.5%)

Observed / Expected Ratios
LoF OE0.10 (0.04–0.30)
0≤0.351.4
Missense OE0.52 (0.45–0.59)
0≤0.61.4
Synonymous OE1.02
0≤1.21.6
LoF obs/exp: 2 / 20.7Missense obs/exp: 152 / 292.6Syn Z: -0.19

ClinVar Variant Classifications

0 submitted variants in ClinVar

ClinVar

Protein Context — Lollipop Plot

MID1 · protein map & ClinVar variants

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

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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Full-Text Mentions
NLP-detected gene mentions in article bodies · via PubTator3
PubTator3
Top 5 full-text resultsSearch PubTator3 ↗
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC
Top 5 resultsSearch Europe PMC ↗

External Resources

Links to major genomics databases and tools

Franklin by Genoox
AI-powered variant curation and clinical analysis
DECIPHER
Genomic variants and phenotypes in rare disease patients