Obesity

Caring for someone with this diagnosis? Eleplan keeps diagnoses, medications, documents and every specialist in one plan.

Start free with Eleplan

Obesity due to melanocortin 4 receptor deficiency

ORPHA:71529Etiological subtype

Also called MC4R deficiency

What it is

Melanocortin 4 receptor (MC4R) deficiency is the commonest form of monogenic obesity identified so far. MC4R deficiency is characterised by severe obesity, an increase in lean body mass and bone mineral density, increased linear growth in early childhood, hyperphagia beginning in the first year of life and severe hyperinsulinaemia, in the presence of preserved reproductive function.

Key facts

Prevalence
1-5 / 10 000 (France)
Age of onset
Infancy, Neonatal
Inheritance
Autosomal dominant, Autosomal recessive
Classified as
Etiological subtype

Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.

Signs and symptoms

These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.

Gene

MC4RDisease-causing germline mutation(s)

ICD-10 codes

E66.8filed under a broader ICD-10 category — shared with 12 other rare diseases

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Related health topics

Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.

Cross-references

MONDO 0019115OMIM 601665OMIM 618406UMLS C4273958

Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.

Powered by Eleplan

A rare diagnosis is just the start. Eleplan keeps the whole care plan in one place.

Diagnoses, medications, documents, appointments, and the whole care team — organized and always in sync, so you are not retelling the same story to every new specialist. With Ellie, your AI care assistant, on top of it. Free to start.