Original Investigations

Human Genetics

, Volume 74, Issue 2, pp 107-112

First online:

Xeroderma pigmentosum (complementation group D) mutation is present in patients affected by trichothiodystrophy with photosensitivity

  • M. StefaniniAffiliated withIstituto di Genetica Biochimica ed Evoluzionistica CNR
  • , P. LagomarsiniAffiliated withIstituto di Genetica Biochimica ed Evoluzionistica CNR
  • , C. F. ArlettAffiliated withMRC Cell Mutation Unit University of Sussex, Falmer
  • , S. MarinoniAffiliated withIstituto per l'Infanzia
  • , C. BorroneAffiliated withIstituto G. Gaslini Div. Pediatrica III
  • , F. CrovatoAffiliated withDivisione Dermatologica, Ospedale Chiavari
  • , G. TrevisanAffiliated withClinica Dermatologica, Università Trieste
  • , G. CordoneAffiliated withIstituto Clinica Pediatrica I, Università Genova
  • , F. NuzzoAffiliated withIstituto di Genetica Biochimica ed Evoluzionistica CNR

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


We studied the response to UV irradiation in cells from four patients, from three apparently unrelated families, affected by trichothiodystrophy (TTD). They showed all the symptoms of this rare autosomal recessive disorder (brittle hair with reduced sulfur content, mental and physical retardation, ichthyosis, peculiar face) together with photosensitivity. We found a decreased rate of duplicative DNA synthesis in stimulated lymphocytes, reduced survival in fibroblasts, and very low levels of unscheduled DNA synthesis (UDS) in Go lymphocytes and fibroblasts after UV irradiation. Complementation studies showed that normal values of UDS are restored in heterokaryons obtained by fusion of TTD cells with normal and xeroderma pigmentosum (XP)-complementation group A-cells. In contrast the defect is not complemented by fusion with XP-complementation group D-fibroblasts.