CDK5RAP2 and microcephaly: CDK5RAP2 PM: Autosomal recessive microcephaly due to biallelic CDK5RAP2 variants [4] characterized by (i) progressive hearing loss due to a specific cochlear malformation (small cochlea and a simplification of the cochlear spiral), (ii) ocular defects, including microphthalmia and retinal pigmentation defects, and (iii) interhypothalamic adhesion [12].