A gene at q31 on human chromosome 1 that is essential for the production of normal spindles in embryonic neuroblasts. ASPM is an abbreviation for abnormal spindle-microcephaly. Most humans suffering from hereditary microcephaly (q.v.) are homozygous for null alleles of this gene. ASPM contains 28 exons and spans 62 kb of genomic sequence. About 5,800 years ago, a new allele of ASPM arose which was subjected to such intense natural selection (q.v.) that it now shows up in about 30 percent of today's humans. See Appendix C, 2005, Lahn et al.; MCPH, neomorph.
Subjects: Genetics and Genomics.