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Trichothiodystrophy: Photosensitive, TTD-P, TTD, Tay syndrome
W Clark Lambert1, Claude E Gagna, Muriel W Lambert
1Department of Pathology and Laboratory Medicine, Room C520, Medical Science Building, UMDNJ-New Jersey Medical School, 185 South Orange Avenue, Newark, New Jersey 07103, USA. lamberwc@umdnj.edu
Advances in Experimental Medicine and Biology
|August 7, 2010
Summary
Trichothiodystrophy (TTD) is a rare, inherited disorder characterized by brittle hair and nails, ichthyosis, and growth retardation. This multisystem disease affects various organs and can present with photosensitivity, linked to DNA repair defects.
Area of Science:
- Genetics and Molecular Biology
- Dermatology
- Neurology
Background:
- Trichothiodystrophy (TTD) is a rare, autosomal recessive disorder characterized by sulfur-deficient brittle hair.
- It is a heterogeneous multisystem disease with neuroectodermal tissues often involved.
- TTD is associated with ichthyosis, growth retardation, and sometimes photosensitivity.
Purpose of the Study:
- To provide a comprehensive overview of Trichothiodystrophy (TTD).
- To highlight the clinical heterogeneity and diagnostic features of TTD.
- To discuss the association between photosensitivity and DNA repair defects in TTD.
Main Methods:
- Review of clinical and genetic literature on TTD.
- Analysis of diagnostic features including hair microscopy and sulfur content.
- Correlation of clinical phenotypes with underlying molecular defects, particularly nucleotide excision repair (NER).
Main Results:
- TTD presents with brittle hair and nails, ichthyosis, intellectual disability, and growth retardation.
- Distinctive "tiger tail" anomaly observed in hair shafts under polarized light microscopy aids diagnosis.
- Approximately 50% of TTD patients exhibit photosensitivity, linked to NER pathway defects (TTDP).
Conclusions:
- TTD is a complex, multisystem disorder with significant clinical variability.
- Diagnostic approaches include characteristic hair anomalies and biochemical analysis.
- Understanding the genetic basis, especially NER defects in photosensitive cases, is crucial for patient management.
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