DO_rare_slim NCIthesaurus trichothiodystrophy A syndrome characterized by sparse, brittle, sulfur-deficient hair that is easily broken and in more severe cases delayed development, significant intellectual disability, and recurrent infections. UMLS_CUI:C1955934 MESH:D054463 disease_ontology DOID:0111866 SNOMEDCT_US_2025_09_01:723551003 MIM:PS601675 NCI:C4924 ORDO:33364 TTD syndrome