TTD
Also written as: TTD — Trichothiodystrophy
Standard abbreviation for trichothiodystrophy, a sulfur-deficient brittle-hair genodermatosis seen in children.
Full Definition
TTD stands for trichothiodystrophy, a rare hereditary multisystem disorder defined by brittle, sulfur-deficient hair due to defects in nucleotide excision repair genes. The abbreviation is universally recognised in pediatric dermatology and genetics literature and may be used after the full term has been introduced. In manuscripts covering overlapping DNA-repair disorders, editors should verify that TTD is not used interchangeably with XP (xeroderma pigmentosum) or CS (Cockayne syndrome), as these are clinically and prognostically distinct entities. Some older literature uses 'BIDS' or 'PIBIDS' to describe phenotypic subsets, which should be retained only if used by the original author with explanation.
Usage
Usage note: Introduce as 'trichothiodystrophy (TTD)' on first use; thereafter TTD is acceptable. Do not conflate with XP or CS.
In Context
- "The genetics team confirmed TTD in a sibling pair presenting with brittle hair and intellectual impairment." — Pediatric genetics consultation note
- "On second mention, the abbreviation TTD was used consistently throughout the review article." — Medical journal manuscript