A subtype of trichothiodystrophy caused by mutation(s) in the MPLKIP gene, encoding M-phase-specific PLK1-interacting protein. The disease is Monarch Disease Ontology id MONDO_0021013 (trichothiodystrophy 4, nonphotosensitive). Also known as: MPLKIP nonphotosensitive trichothiodystrophy, Pollitt syndrome, TTD4, nonphotosensitive trichothiodystrophy caused by mutation in MPLKIP.