Chapter VI
Diseases of the nervous system
(G00-G99)

Diseases of myoneural junction and muscle
(G70-G73)

G70 Myasthenia gravis and other myoneural disorders
Excludes: botulism ( A05.1 )
transient neonatal myasthenia gravis ( P94.0 )
G70.0 Myasthenia gravis
Use additional external cause code (Chapter XX), if desired, to identify drug, if drug-induced.
G70.1 Toxic myoneural disorders
Use additional external cause code (Chapter XX), if desired, to identify toxic agent.
G70.2 Congenital and developmental myasthenia
G70.8 Other specified myoneural disorders
G70.9 Myoneural disorder, unspecified

G71 Primary disorders of muscles
Excludes: arthrogryposis multiplex congenita ( Q74.3 )
metabolic disorders ( E70-E90 )
myositis ( M60.- )
G71.0 Muscular dystrophy
Muscular dystrophy:
· autosomal recessive, childhood type, resembling Duchenne or Becker
· benign [Becker]
· benign scapuloperoneal with early contractures [Emery-Dreifuss]
· distal
· facioscapulohumeral
· limb-girdle
· ocular
· oculopharyngeal
· scapuloperoneal
· severe [Duchenne]
Excludes: congenital muscular dystrophy:
· NOS ( G71.2 )
· with specific morphological abnormalities of the muscle fibre ( G71.2 )
G71.1 Myotonic disorders
Dystrophia myotonica [Steinert]
Myotonia:
· chondrodystrophic
· drug-induced
· symptomatic
Myotonia congenita:
· NOS
· dominant [Thomsen]
· recessive [Becker]
Neuromyotonia [Isaacs]
Paramyotonia congenita
Pseudomyotonia
Use additional external cause code (Chapter XX), if desired, to identify drug, if drug-induced.
G71.2 Congenital myopathies
Congenital muscular dystrophy:
· NOS
· with specific morphological abnormalities of the muscle fibre
Disease:
· central core
· minicore
· multicore
Fibre-type disproportion
Myopathy:
· myotubular (centronuclear)
· nemaline
G71.3 Mitochondrial myopathy, not elsewhere classified
G71.8 Other primary disorders of muscles
G71.9 Primary disorder of muscle, unspecified
Hereditary myopathy NOS

G72 Other myopathies
Excludes: arthrogryposis multiplex congenita ( Q74.3 )
dermatopolymyositis ( M33.- )
ischaemic infarction of muscle ( M62.2 )
myositis ( M60.- )
polymyositis ( M33.2 )
G72.0 Drug-induced myopathy
Use additional external cause code (Chapter XX), if desired, to identify drug.
G72.1 Alcoholic myopathy
G72.2 Myopathy due to other toxic agents
Use additional external cause code (Chapter XX), if desired, to identify toxic agent.
G72.3 Periodic paralysis
Periodic paralysis (familial):
· hyperkalaemic
· hypokalaemic
· myotonic
· normokalaemic
G72.4 Inflammatory myopathy, not elsewhere classified
G72.8 Other specified myopathies
G72.9 Myopathy, unspecified

G73* Disorders of myoneural junction and muscle in diseases classified elsewhere
G73.0* Myasthenic syndromes in endocrine diseases
Myasthenic syndromes in:
· diabetic amyotrophy ( E10-E14+ with common fourth character .4)
· thyrotoxicosis [hyperthyroidism] ( E05.-+ )
G73.1* Eaton-Lambert syndrome ( C80+ )
G73.2* Other myasthenic syndromes in neoplastic disease ( C00-D48+ )
G73.3* Myasthenic syndromes in other diseases classified elsewhere
G73.4* Myopathy in infectious and parasitic diseases classified elsewhere
G73.5* Myopathy in endocrine diseases
Myopathy in:
· hyperparathyroidism ( E21.0-E21.3+ )
· hypoparathyroidism ( E20.-+ )
Thyrotoxic myopathy ( E05.-+ )
G73.6* Myopathy in metabolic diseases
Myopathy in:
· glycogen storage disease ( E74.0+ )
· lipid storage disorders ( E75.-+ )
G73.7* Myopathy in other diseases classified elsewhere
Myopathy in:
· rheumatoid arthritis ( M05-M06+ )
· scleroderma ( M34.8+ )
· sicca syndrome [Sjögren] ( M35.0+ )
· systemic lupus erythematosus ( M32.1+ )