Chapter XVII

Congenital malformations, deformations and chromosomal abnormalities
(Q00-Q99)

Congenital malformations of the nervous system
(Q00-Q07)

Q00 Anencephaly and similar malformations
Q00.0 Anencephaly
Acephaly
Acrania
Amyelencephaly
Hemianencephaly
Hemicephaly
Q00.1 Craniorachischisis
Q00.2 Iniencephaly

Q01 Encephalocele
Includes: encephalomyelocele
hydroencephalocele
hydromeningocele, cranial
meningocele, cerebral
meningoencephalocele
Excludes: Meckel-Gruber syndrome ( Q61.9 )
Q01.0 Frontal encephalocele
Q01.1 Nasofrontal encephalocele
Q01.2 Occipital encephalocele
Q01.8 Encephalocele of other sites
Q01.9 Encephalocele, unspecified

Q02 Microcephaly
Hydromicrocephaly
Micrencephalon
Excludes: Meckel-Gruber syndrome ( Q61.9 )

Q03 Congenital hydrocephalus
Includes: hydrocephalus in newborn
Excludes: Arnold-Chiari syndrome ( Q07.0 )
hydrocephalus:
· acquired ( G91.- )
· due to congenital toxoplasmosis ( P37.1 )
· with spina bifida ( Q05.0-Q05.4 )
Q03.0 Malformations of aqueduct of Sylvius
Aqueduct of Sylvius:
· anomaly
· obstruction, congenital
· stenosis
Q03.1 Atresia of foramina of Magendie and Luschka
Dandy-Walker syndrome
Q03.8 Other congenital hydrocephalus
Q03.9 Congenital hydrocephalus, unspecified

Q04 Other congenital malformations of brain
Excludes: cyclopia ( Q87.0 )
macrocephaly ( Q75.3 )
Q04.0 Congenital malformations of corpus callosum
Agenesis of corpus callosum
Q04.1 Arhinencephaly
Q04.2 Holoprosencephaly
Q04.3 Other reduction deformities of brain
Absence
Agenesis
Aplasia
Hypoplasia
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of part of brain
Agyria
Hydranencephaly
Lissencephaly
Microgyria
Pachygyria
Excludes: congenital malformations of corpus callosum ( Q04.0 )
Q04.4 Septo-optic dysplasia
Q04.5 Megalencephaly
Q04.6 Congenital cerebral cysts
Porencephaly
Schizencephaly
Excludes: acquired porencephalic cyst ( G93.0 )
Q04.8 Other specified congenital malformations of brain
Macrogyria
Q04.9 Congenital malformation of brain, unspecified
Congenital:
· anomaly
· deformity
· disease or lesion
· multiple anomalies
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NOS of brain

Q05 Spina bifida
Includes: hydromeningocele (spinal)
meningocele (spinal)
meningomyelocele
myelocele
myelomeningocele
rachischisis
spina bifida (aperta)(cystica)
syringomyelocele
Excludes: Arnold-Chiari syndrome ( Q07.0 )
spina bifida occulta ( Q76.0 )
Q05.0 Cervical spina bifida with hydrocephalus
Q05.1 Thoracic spina bifida with hydrocephalus
Spina bifida:
· dorsal
· thoracolumbar
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with hydrocephalus
Q05.2 Lumbar spina bifida with hydrocephalus
Lumbosacral spina bifida with hydrocephalus
Q05.3 Sacral spina bifida with hydrocephalus
Q05.4 Unspecified spina bifida with hydrocephalus
Q05.5 Cervical spina bifida without hydrocephalus
Q05.6 Thoracic spina bifida without hydrocephalus
Spina bifida:
· dorsal NOS
· thoracolumbar NOS
Q05.7 Lumbar spina bifida without hydrocephalus
Lumbosacral spina bifida NOS
Q05.8 Sacral spina bifida without hydrocephalus
Q05.9 Spina bifida, unspecified

Q06 Other congenital malformations of spinal cord
Q06.0 Amyelia
Q06.1 Hypoplasia and dysplasia of spinal cord
Atelomyelia
Myelatelia
Myelodysplasia of spinal cord
Q06.2 Diastematomyelia
Q06.3 Other congenital cauda equina malformations
Q06.4 Hydromyelia
Hydrorachis
Q06.8 Other specified congenital malformations of spinal cord
Q06.9 Congenital malformation of spinal cord, unspecified
Congenital:
· anomaly
· deformity
· disease or lesion
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NOS of spinal cord or meninges

Q07 Other congenital malformations of nervous system
Excludes: familial dysautonomia [Riley-Day] ( G90.1 )
neurofibromatosis (nonmalignant) ( Q85.0 )
Q07.0 Arnold-Chiari syndrome
Q07.8 Other specified congenital malformations of nervous system
Agenesis of nerve
Displacement of brachial plexus
Jaw-winking syndrome
Marcus Gunn's syndrome
Q07.9 Congenital malformation of nervous system, unspecified
Congenital:
· anomaly
· deformity
· disease or lesion
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NOS of nervous system