Inherited disorder characterized by coloboma,
microcephaly, porencephaly, and hydronephrosis, in which an affected
individual has a head circumference less than 3 standard deviations below
the ageand sex-related mean. All affected individuals are mentally
Primary Autosomal Recessive Microcephaly; MCPH
Approximately 1:250,000 live
births. True microcephaly is inherited as an autosomal recessive trait. It is
genetically heterogenous, with at least five loci mapped: MCPH1 to
chromosome 8p23; MCPH2 to locus 19q13.1-q13.2; MCPH3 at 9q34; MCPH4 at
15q15-q21; and MCPH5 to 1q31, which is a mutant of the ASPM (abnormal
spindle-like, microcephaly associated) gene.
Microcephaly with sloping forehead, narrow
forehead, and flat occiput. It is associated with mental deficiency and
seizures. A small but apparently normally formed brain is the reason for the
reduced head circumference.
There are no specific considerations reported.
Assessment of severity of seizures and knowledge of treatment.
Pattison L, Crow YJ, Deeble VJ, et al: A fifth locus for primary
autosomal recessive microcephaly maps to chromosome 1q31. Am J Hum Genet