2006 ICD-9-CM Volume 1 Diagnosis Codes Home > Congenital Anomalies 740-759 > Other Congenital Anomalies Of Nervous System 742.* > 2006 ICD-9-CM Diagnosis 742.2 Congenital reduction deformities of brain View the most recent version of ICD-9-CM 742.2 Anterior midline brain, cranial, and facial malformations resulting from the failure of the embryonic prosencephalon to undergo segmentation and cleavage. Alobar prosencephaly is the most severe form and features anophthalmia; cyclopia; severe MENTAL RETARDATION; CLEFT LIP; CLEFT PALATE; SEIZURES; and microcephaly. Semilobar holoprosencepaly is characterized by hypotelorism, microphthalmia, coloboma, nasal malformations, and variable degrees of mental retardation. Lobar holoprosencephaly is associated with mild (or absent) facial malformations and intellectual abilities that range from mild mental retardation to normal. Holoprosencephaly is associated with CHROMOSOME ABNORMALITIES. 742.2 is a specific code that can be used to specify a diagnosis 742.2 contains 30 index entries View the ICD-9-CM Volume 1 742.* hierarchy Alternate Terminology Absence of part of brain Agenesis of part of brain Agyria Aplasia of part of brain Arhinencephaly Holoprosencephaly Hypoplasia of part of brain Microgyria  Index entries containing 742.2: Absence (organ or part) (complete or partial) brain 740.0 specified part 742.2 cerebellum (congenital) (vermis) 742.2 corpus callosum (congenital) 742.2 vermis of cerebellum 742.2 Agenesis - see also Absence, by site, congenital brain 740.0 specified part 742.2 cerebellum 742.2 corpus callosum 742.2 vermis of cerebellum 742.2 Agyria 742.2 Anomaly, anomalous (congenital) (unspecified type) 759.9 brain 742.9 reduction 742.2 Aplasia - see also Agenesis brain 740.0 specified part 742.2 cerebellar 742.2 corpus callosum 742.2 Arhinencephaly 742.2 Arnold-Chiari obstruction or syndrome (see also Spina bifida) 741.0 type IV 742.2 Arrhinencephaly 742.2 due to trisomy 13 (13-15) 758.1 trisomy 18 (16-18) 758.2 Chiari's malformation type IV 742.2 Deformity 738.9 brain (congenital) 742.9 reduction 742.2 reduction (extremity) (limb) 755.4 brain 742.2 Holoprosencephaly 742.2 due to trisomy 13 758.1 trisomy 18 758.2 Hypoplasia, hypoplasis 759.89 brain 742.1 gyri 742.2 specified part 742.2 cerebellum 742.2 corpus callosum 742.2 Lissencephalia, lissencephaly 742.2 Malformation (congenital) - see also Anomaly Chiari type IV 742.2 Microgyria (congenital) 742.2 Nondevelopment brain 742.1 specified part 742.2 Polymicrogyria 742.2 Syndrome - see also Disease Arnold-Chiari (see also Spina bifida) 741.0 type IV 742.2