Traits

Traits linked to MANBA

mannosidase beta

The Human Phenotype Ontology links 18 traits to MANBA, by body system: features seen in people with one of the gene's rare conditions.

Abnormality of the nervous system

Trait	How often it is seen
Intellectual disability	Always
More active than typical	Always
Epilepsy	Very often (80–99%)
Demyelinating peripheral neuropathy	Sometimes (5–29%)
Abnormal speech pattern	Not recorded
Aggressive behavior	Not recorded

Laboratory abnormality

Trait	How often it is seen
Decreased circulating beta-mannosidase activity	Always
Reduced tissue beta-mannosidase activity	Always
Increased urinary disaccharide excretion	Not recorded

Abnormality of head or neck

Trait	How often it is seen
Abnormal facial shape	Very often (80–99%)
Tortuosity of conjunctival vessels	Not recorded

Abnormality of the immune system

Trait	How often it is seen
Recurrent respiratory infections	Very often (80–99%)
Recurrent infections	Not recorded

Abnormality of the musculoskeletal system

Trait	How often it is seen
Generalized decreased muscle tone	Not recorded
Low muscle tone	Not recorded

Abnormality of the cardiovascular system

Trait	How often it is seen
Angiokeratoma	Not recorded

Abnormality of the digestive system

Trait	How often it is seen
Hypoplasia of the abdominal wall musculature	Very often (80–99%)

Abnormality of the ear

Trait	How often it is seen
Hearing impairment	Very often (80–99%)

How often is among people with one of the gene's conditions, the most often across them, as the Human Phenotype Ontology records it. These pages describe traits and the research behind them; they are not a diagnosis, and a doctor or genetic counsellor is the person to ask about symptoms.

Where this comes from

The Human Phenotype Ontology, release 2026-09-01: the traits linked to MANBA and how often each is seen. Find out more at hpo.jax.org.

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