raremaprare-disease reference indexOrphadata 2026-06-23 · HPO 2026-09-01
ORPHA:65684

Monomelic amyotrophy

Synonyms: Benign focal amyotrophy · Hirayama disease · JMADUE · Juvenile muscular atrophy of distal upper extremity · Juvenile muscular atrophy of the distal upper limb

Type
Disease
Group
Disorder
Inheritance
Unknown
Age of onset
Adolescent, Adult
Status
active

Monomelic amyotrophy (MA) is a rare benign lower motor neuron disorder characterized by muscular weakness and wasting in the distal upper extremities during adolescence followed by a spontaneous halt in progression and a stabilization of symptoms.

1

Names in Orphadata languages

12 of 12 languages
LangNameSynonyms
enMonomelic amyotrophyBenign focal amyotrophy · Hirayama disease · JMADUE · Juvenile muscular atrophy of distal upper extremity · Juvenile muscular atrophy of the distal upper limb
frAmyotrophie monoméliqueAmyotrophie focale bénigne · Atrophie musculaire distale juvénile des extrémités supérieures · Atrophie musculaire distale juvénile du membre supérieur · JMADUE · Maladie de Hirayama
deAmyotrophie, monomelischeAmyotrophie, benigne fokale · Hirayama-Krankheit · JMADUE · Juvenile Muskelatrophie der distalen oberen Gliedmaßen
esAtrofia monomélicaJMADUE · Amiotrofia focal benigna · Atrofia muscular juvenil de las extremidades superiores distales · Enfermedad de Hirayama
itAmiotrofia monomelicaAmiotrofia focale benigna · Atrofia muscolare distale giovanile dell'estremità superiore · Atrofia muscolare giovanile distale dell'arto superiore · JMADUE · Malattia di Hirayama
nlMonomelische amyotrofieGoedaardige focale amyotrofie · JMADUE · Juveniele musculaire atrofie van de distale bovenste ledematen · Juveniele musculaire atrofie van distale bovenste extremiteit · Juveniele spieratrofie van de distale bovenste ledematen · Juveniele spieratrofie van distale bovenste extremiteit · Ziekte van Hirayama
ptAmiotrofia monomélicaAmiotrofia focal benigna · Atrofia muscular distal do membro superior, juvenil · Doença de Hirayama
plAmiotrofia monomelicznaChoroba Hirayama · JMADUE · Łagodna ogniskowa amiotrofia · Młodzieńcza atrofia mięśni dystalnych kończyn górnych
csMonomelická amyotrofieBenigní fokální amyotrofie · Hirayamova choroba · JMADUE · Juvenilní svalová atrofie horní končetiny distálně
ukМономелічна аміотрофіяДоброякісна фокальна аміотрофія · Хвороба Хіраяма · JMADUE · Ювенільна мязова атрофія дистального відділу верхньої кінцівки · Ювенільна мязова атрофія дистального відділу верхньої кінцівки
zh单肢肌萎缩青少年上肢远端肌萎缩症
trMonomelik amiyotrofiJMADUE · Hirayama hastalığı · Selim fokal amyotrofi · Distal üst ekstremitenin jüvenil kas atrofisi · Distal üst ekstremitenin jüvenil kas atrofisi

Definition in:

2

Cross-references

qualifier = Orphanet mapping relation
SourceCodeQualifierICD relationValidation
OMIM602440Evalidated
ICD-10G12.8NTBTattributedvalidated
ICD-118B60.6Especificvalidated
MONDO0011224Evalidated
MeSHC538253Evalidated
UMLSC1865384Evalidated
GARD9697Evalidated
MedDRA10069681Evalidated

E exact · NTBT this ORPHAcode is narrower than the target · BTNT broader than the target · ND not decided.

3

Classification

Preferential parent (Orphanet linearisation):

Parents in the classifications (1):

No children.

4

Genes

2 direct
GeneAssociationStatusHGNCEnsemblOMIMLocusNameSource of validation
CEP126Major susceptibility factor inAssessedHGNC:29264ENSG0000011031861463411q22.1centrosomal protein 12622264561[PMID]
CPLANE1Major susceptibility factor inAssessedHGNC:25801ENSG000001976036145715p13.2ciliogenesis and planar polarity effector complex subunit 122264561[PMID]
5

Prevalence and incidence

1 record
TypeClassValueAreaQualificationValidationSource
Point prevalenceUnknown—WorldwideClass onlyNot yet validatedORPHANET

Value is Orphadata's ValMoy: the mean estimate per 100 000 for prevalence and incidence, the number of cases or families for case reports.

6

HPO phenotypes

10 annotations · validated 2016-06-01
HPOTerm (as annotated by Orphanet)Diagnostic
Very frequent (99-80%)
HP:0002817Abnormality of the upper limb
HP:0007149Distal upper limb amyotrophy
HP:0003457EMG abnormality
HP:0001324Muscle weakness
Frequent (79-30%)
HP:0003134Abnormality of peripheral nerve conduction
HP:0002398Degeneration of anterior horn cells
Occasional (29-5%)
HP:0100022Abnormality of movement
HP:0002715Abnormality of the immune system
HP:0002380Fasciculations
HP:0001337Tremor

Run the differential on the 4 obligate / very frequent terms

Annotation source: 22032508[PMID]

7

Sources for this card