Progressive osseous heteroplasia

What it is

Progressive osseous heteroplasia (POH) is a rare genetic bone disorder characterized clinically by progressive extraskeletal bone formation presenting in early life with cutaneous ossification, that progressively involves subcutaneous and then subsequently deep connective tissues, including muscle and fascia. POH overlaps with a number of related genetic disorders including Albright hereditary osteodystrophy, pseudohypoparathyroidism, and primary osteoma cutis, that share the common features of superficial heterotopic ossification in association with inactivating mutations of GNAS gene (20q13.2-q13.3), coding for guanine nucleotide-binding proteins. POH can, however, be distinguished clinically by the deep and progressive nature of the heterotopic bone formation.

Key facts

Prevalence

<1 / 1 000 000

Age of onset

Childhood, Infancy

Inheritance

Autosomal dominant

Classified as

Malformation syndrome

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

ICD-10 codes

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