IFT88 and ciliopathy: Because residual CENP-F protein was observed in the fibroblasts of our MCPH patient, a dosage-dependent mechanism could be proposed in which complete loss of function of both CENPF alleles would lead to an embryonic lethal ciliopathy phenotype, whereas residual CENP-F activity would be sufficient for normal ciliary targeting of IFT88 and, perhaps, a less severe phenotype.