Jada Bascom Foundation
All conditions

Inherited metabolic disorders

Alpha-mannosidosis

Also called: MAN2B1 deficiency · alpha-mannosidase deficiency · Alpha-D-mannosidosis · Lysosomal alpha-mannosidase deficiency

What a donor has to do with this

A transplant is not a standard part of treating this condition. It is used rarely, in particular situations, and most people diagnosed with it will not have one.

This is our reading of published transplant guidelines for this condition, not a measurement of how many people need a donor. Where a source actually counted donors, the figure and the people it counted are shown further down. Where none did, we say so rather than estimate.

This page is not written out in full yet

We have not written this condition out in full yet. What is on this page — how a donor fits in, who it affects, and the sources behind that — is researched and linked, but the plain-English explanation of the condition itself is still to come.

What the evidence says

Who it affects
Typical onset/diagnosis: manifestations begin from birth through childhood, with severe disease evident in infancy; an international 17-patient cohort had median diagnosis at 2.5 years. Evidence: international multicenter cohort (published 2012); no markedly enriched population was identified.
Treatments other than a transplant
Lamzede (velmanase alfa) — approved — United States, 2023 — Treats non-central-nervous-system manifestations.; Lamzede (velmanase alfa) — approved — European Union, 2018 — Treats non-central-nervous-system manifestations.
If a transplant is used, the cells come from
bone marrow: used in 6 of 16 patients with reported first-graft source; mobilized peripheral blood stem cells: used in 6 of 16 patients with reported first-graft source; umbilical cord blood: used in 4 of 16 patients with reported first-graft source; dominance: no single source dominated; bone marrow and peripheral blood were tied among 16 patients with a reported first-graft source in the international 17-patient cohort across Europe, the United States, and Japan; first transplants occurred in 1997–2008 and the article was published in 2011
How often the donor was unrelated
Not reported. No source we could read states this for this condition, so we do not give a number. An estimate here would be a guess dressed as evidence.

Where this gets complicated

Velmanase alfa does not directly treat central nervous system disease, while allogeneic HCT carries material mortality and graft-versus-host risk.; Comparative evidence between ERT and HCT is nonrandomized and affected by era and selection bias.

Written for transplant clinicians, not for patients. We quote it so you can see what the guidance actually says:
“Hematopoietic SCT (HSCT) is usually recommended as a therapeutic option though reports are anecdotal to date.”

It describes what teams consider in general. It cannot say what applies to any one person. Read the source.

Registries need people

An unrelated donor is not a usual part of treating this condition. Registering still matters, for the many conditions where it is.

Joining a registry is a cheek swab and a short health form. You are not matched to a condition — you are matched to a person, and it could be someone with any of the conditions in this library. You are contacted only if you turn out to be a possible match for someone, and you can ask questions and decline before anything else happens.

Find your registry

Related conditions

Others in inherited metabolic disorders. They are genuinely different diseases with different treatments — the group name is not a diagnosis.

Where this came from