CDK5RAP2 and autosomal recessive primary microcephaly: The 25-kb maternally inherited deletion was located within the 75-kb paternally inherited deletion, and therefore inheritance of abnormal allele from both parents led to a 25-kb homozygous and a 50-kb heterozygous deletion in the proband (Fig. 4); 2): a 1-year-old boy was found to have a 74-kb homozygous deletion of the CDK5RAP2 gene in a region of homozygosity (Additional file 3: Figure S2) which led to autosomal recessive primary microcephaly-3 (OMIM #604804).