MAN1B1

Chr 9AR

mannosidase alpha class 1B member 1

Also known as: ERMAN1, ERManI, MANA-ER, MRT15

This gene encodes an alpha-1,2-mannosidase that trims mannose residues from N-linked glycans in the endoplasmic reticulum, functioning in glycoprotein quality control and targeting misfolded proteins for degradation. Biallelic mutations cause Rafiq syndrome, an autosomal recessive intellectual disability disorder. The gene shows moderate constraint against loss-of-function variants (LOEUF 0.83), suggesting some tolerance to heterozygous disruption.

OMIMResearchSummary from RefSeq, OMIM, UniProt
DNmechanismARLOEUF 0.831 OMIM phenotype
Clinical SummaryMAN1B1
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Gene-Disease Validity (ClinGen)
MAN1B1-congenital disorder of glycosylation · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.83LOEUF
pLI 0.000
Z-score 2.31
OE 0.56 (0.390.83)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
-0.73Z-score
OE missense 1.10 (1.021.19)
448 obs / 406.8 exp
Tolerant

Tolerant to missense variation

Observed / Expected Ratios
LoF OE0.56 (0.390.83)
00.351.4
Missense OE1.10 (1.021.19)
00.61.4
Synonymous OE1.31
01.21.6
LoF obs/exp: 18 / 32.1Missense obs/exp: 448 / 406.8Syn Z: -3.25
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveMAN1B1-related intellectual developmental disorderOTHERAR

Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.

DN
0.6649th %ile
GOF
0.5758th %ile
LOF
0.3260th %ile

The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

MAN1B1 · 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

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 ↗