MPLKIP

M-phase-specific PLK1-interacting protein (TTD non-photosensitive 1 protein) is a is_associated_with::protein that in is_associated_with::humans is encoded by the MPLKIP is_associated_with::gene (previously known as C7orf11). Patients with an inherited defect in both alleles of the gene suffer from is_associated_with::trichothiodystrophy (TTD), a disease hallmarked by brittle hair and nails and usually by developmental difficulties as well. One patient carries a is_associated_with::homozygous deletion of the whole gene area, which indicates that the gene is not essential for embryonic development. TTD can be diagnosed by the presence of tigertail-striped patterns in hair visible under polarised light microscopy, or biochemically by a reduced is_associated_with::cystein content of the hairs. Only a minority of the TTD cases carry a MPLKIP defect: more frequently, the gene is_associated_with::ERCC2 is mutated, which encodes a subunit of the protein complex is_associated_with::TFIIH that is required for general transcription and for is_associated_with::nucleotide excision repair of DNA damage.