Trichothiodystrophy, a transcription syndrome.
Trichothiodystrophy (TTD) is a rare genetic disorder characterized by a hair dysplasia and associated with numerous symptoms affecting mainly organs derived from the neuroectoderm. About half of TTD patients exhibit photosensitivity because their nucleotide-excision repair pathway (NER) does not remove UV-induced DNA lesions efficiently. However, they do not present the skin cancer susceptibility expected from such an NER disorder. Their deficiencies result from phenotype-specific mutations in either XPB or XPD. These genes encode the helicase subunits of TFIIH, a DNA repair factor that is also required for transcription of class II genes. Thus, time- and tissue-specific impairments of transcription might explain the developmental and neurological symptoms of TTD. In a third group of photosensitive patients, TTD-A, no mutation has been identified, although TFIIH amount is reduced.
Bergmann
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E
Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, BP 163, 67404 Illkirch Cedex, C.U. de Strasbourg, France.
Egly
J M
JM
D000015:Abnormalities, Multiple / Q000235:genetics*; D004265:DNA Helicases; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D006201:Hair Diseases / Q000235:genetics*; D006801:Humans; D007057:Ichthyosis / Q000235:genetics; D020752:Neurocutaneous Syndromes / Q000235:genetics; D010641:Phenotype; D010787:Photosensitivity Disorders / Q000235:genetics*; D011506:Proteins / Q000235:genetics; D051758:Transcription Factor TFIIH; D014157:Transcription Factors / Q000235:genetics; D019473:Transcription Factors, TFII; D014158:Transcription, Genetic / Q000235:genetics; D014466:Ultraviolet Rays; D051759:Xeroderma Pigmentosum Group D Protein
D004268:DNA-Binding Proteins; D011506:Proteins; D014157:Transcription Factors; D019473:Transcription Factors, TFII; C072022:XPBC-ERCC-3 protein; D051758:Transcription Factor TFIIH; D004265:DNA Helicases; D051759:Xeroderma Pigmentosum Group D Protein; C497292:ERCC2 protein, human