Congenital myopathy

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

Start free with Eleplan

Congenital myopathy with excess of thin filaments

ORPHA:98904Disease

Also called Actin myopathy

What it is

A rare, genetic, congenital myopathy disorder characterized by variable degrees of muscular weakness, frequently associated with severe nemaline myopathy-like disease (including neonatal hypotonia, lack of spontaneous movements, feeding and swallowing difficulties, frequent respiratory infections, respiratory insufficiency, early death), and histopathologic findings of large, densely packed, subsarcolemmal accumulations of thin, actin-immunopositive filaments (with or without intranuclear nemaline rods) on muscle biopsy.

Key facts

Inheritance
Autosomal dominant
Classified as
Disease

Recorded for the broader condition

Prevalence
1-9 / 100 000 (United States)Congenital myopathy

Orphanet records these for the broader condition rather than for this specific form. They are a starting point, not a figure for this subtype — subtypes often differ, and some are defined by being rarer than the condition they sit under.

Gene

ACTA1Disease-causing germline mutation(s)

ICD-10 codes

G71.2filed under a broader ICD-10 category — shared with 56 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.

Benefit programs to look at

Programs whose eligibility touches the same ICD-10 categories. Eligibility is decided by the administering agency, never by this page.

Cross-references

MONDO 8070OMIM 161800OMIM 620265UMLS C3711389

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.