Trichothiodystrophy (TTD)

2000-10-01   Claude Viguié  

Identity

Name

Trichothiodystrophy (TTD)

Alias

Ichtyosis, brittle hair, intellectual impairment, decreased fertility, and short stature syndrome (IBIDS)

Inheritance

recessive autosomal

Omim

234050 , 601675 , 616390 , 616395

Mesh

C536559;D054463

Orphanet

33364 Trichothiodystrophy

Umls

C1955934;C0740342

Clinics

Phenotype and clinics

  • Photosensitivity, Ichtiosys, Brittle hair, Intellectual impairment, Decreased fertility, Short stature (PIBIDS syndrome).
  • photosensitivity is absent in 50% of cases (therefore called IBIDS syndrome).

    • Neoplastic risk

    this familial disease IS NOT a cancer prone disease but it involves the same complementation groups as in xeroderma pigmentosum and Cockayne syndrome (XPD, XPB), and share defects in similar genes

    Prognosis

    depends on the DNA repair defect (photosensitivity: XPD-ERCC2, XPB-ERCC3, TTD-A) and on the transcription errors (other signs)

    Cytogenetics

    Inborn condition

    no known chromosome abnormalities

    Genes involved and Proteins

    Note

    the DNA repair defect is found in 3 classes:
  • patient with TTD-A group (low level of the TFIIH transcription factor),
  • patients mutated in the XPB gene (TTD\/XPB), involving XPB, also called ERCC3, located in 2q21; and
  • all the other patients mutated in the XPD gene (TTD\/XPD), involving XPD, also called ERCC2, located in 19q13

    • Article Bibliography

    Pubmed IDLast YearTitleAuthors
    106888652000Nucleotide excision repair and human syndromes.de Boer J et al
    104166151999Mouse model for the DNA repair/basal transcription disorder trichothiodystrophy reveals cancer predisposition.de Boer J et al