| | T cell immunodeficiency primary |
| | TRAPS (TNF-receptor-associated periodic syndrome) |
| | Taurodontia absent teeth sparse hair |
| | Teebi Naguib Alawadi syndrome |
| | Teeth noneruption of with maxillary hypoplasia and genu valgum |
| | Tel Hashomer camptodactyly syndrome |
| | Telangiectasia ataxia variant V1 |
| | Telangiectasia, hereditary hemorrhagic |
| | Telecanthus hypertelorism pes cavus |
| | Telecanthus with associated abnormalities |
| | Telencephalic leukoencephalopathy |
| | Telfer Sugar Jaeger syndrome |
| | Temporal epilepsy, familial |
| | Temporomandibular ankylosis |
| | Temporomandibular joint dysfunction (TMJ) |
| | Ter Haar Hamel Hendricks syndrome |
| | Tethered spinal cord disease |
| | Tetraamelia ectodermal dysplasia |
| | Tetraamelia multiple malformations |
| | Tetraamelia pulmonary hypoplasia |
| | Tetrahydrobiopterin deficiencies |
| | Thalamic degeneration symmetrical infantile |
| | Thalamic degenerescence infantile |
| | Thanatophoric dysplasia Glasgow variant |
| | Thanatophoric dysplasia cloverleaf skull |
| | Thanos Stewart Zonana syndrome |
| | Theodor Hertz Goodman syndrome |
| | Thiemann epiphyseal disease |
| | Thin ribs tubular bones dysmorphism |
| | Thiopurine S methyltranferase deficiency |
| | Thomas Jewett Raines syndrome |
| | Thompson Baraitser syndrome |
| | Thong Douglas Ferrante syndrome |
| | Thoracic dysplasia hydrocephalus syndrome |
| | Thoraco abdominal enteric duplication |
| | Thoraco limb dysplasia Rivera type |
| | Thoracolaryngopelvic dysplasia |
| | Thost-Unna palmoplantar keratoderma |
| | Thrombocytopathy asplenia miosis |
| | Thrombocytopenia Robin sequence |
| | Thrombocytopenia cerebellar hypoplasia short stature |
| | Thrombocytopenia chromosome breakage |
| | Thrombocytopenia multiple congenital anomaly |
| | Thrombocytopenic purpura, autoimmune |
| | Thrombomodulin anomalies, familial |
| | Thrombotic microangiopathy, familial |
| | Thumb absence hypoplastic halluces |
| | Thumb absent short stature immune deficiency |
| | Thumb deformity, alopecia, pigmentation anomaly |
| | Thumb stiff brachydactyly mental retardation |
| | Thymic renal anal lung dysplasia |
| | Thyrocerebrorenal syndrome |
| | Thyroid carcinoma, follicular |
| | Thyroid carcinoma, papillary (TPC) |
| | Thyroid hormone plasma membrane transport defect |
| | Thyroid, renal and digital anomalies |
| | Tibia absent polydactyly arachnoid cyst |
| | Tibiae bowed radial anomalies osteopenia fracture |
| | Tibial aplasia ectrodactyly |
| | Tibial aplasia ectrodactyly hydrocephalus |
| | Tibial hemimelia cleft lip palate |
| | Tollner Horst Manzke syndrome |
| | Toluene antenatal infection |
| | Tome Brune Fardeau syndrome |
| | Toni Debre Fanconi maladie |
| | Toriello Lacassie Droste syndrome |
| | Toriello-Higgins-Miller syndrome |
| | Torticollis keloids cryptorchidism renal dysplasia |
| | Tosti Misciali Barbareschi syndrome |
| | Total Hypotrichosis, Mari type |
| | Touraine-Solente-Gole syndrome |
| | Toxopachyoteose diaphysaire tibio peroniere |
| | Tracheobronchopathia osteoplastica |
| | Tracheoesophageal fistula |
| | Tracheoesophageal fistula symphalangism |
| | Tracheophageal fistula hypospadias |
| | Tranebjaerg Svejgaard syndrome |
| | Transcobalamin II deficiency |
| | Transient erythroblastopenia of childhood |
| | Transient neonatal arthrogryposis |
| | Transitional cell carcinoma |
| | Transplacental infections |
| | Transposition of great vessels |
| | Transverse limb deficiency hemangioma |
| | Treacher Collins syndrome |
| | Treft Sanborn Carey syndrome |
| | Tremor hereditary essential |
| | Tricho dento osseous syndrome type 1 |
| | Tricho odonto onycho dermal syndrome |
| | Tricho odonto onychodysplasia syndactyly dominant type |
| | Tricho onycho hypohidrotic dysplasia |
| | Tricho retino dento digital syndrome |
| | Tricho-dento-osseous syndrome |
| | Tricho-hepato-enteric syndrome |
| | Trichodermodysplasia dental alterations |
| | Trichodysplasia xeroderma |
| | Trichoepithelioma multiple familial |
| | Trichomegaly cataract hereditary spherocytosis |
| | Trichomegaly retina pigmentary degeneration dwarfi |
| | Trichoodontoonychial dysplasia |
| | Trichorhinophalangeal syndrome type I |
| | Trichorhinophalangeal syndrome type II |
| | Trichorhinophalangeal syndrome type III |
| | Trichothiodystrophy sun sensitivity |
| | Trigonocephaly bifid nose acral anomalies |
| | Trigonocephaly broad thumbs |
| | Trigonocephaly ptosis coloboma |
| | Trigonocephaly ptosis mental retardation |
| | Trigonomacrocephaly tibial defect polydactyly |
| | Trihydroxycholestanoylcoa oxidase isolated deficiency |
| | Trimethadione antenatal infection |
| | Triose phosphate-isomerase deficiency |
| | Triphalangeal thumb non opposable |
| | Triphalangeal thumb polysyndactyly syndrome |
| | Triphalangeal thumbs brachyectrodactyly |
| | Trismus pseudocamptodactyly syndrome |
| | Trophoblastic Neoplasms (gestational trophoblastic disease) |
| | Tropical Spastic Paraparesis |
| | Trueb Burg Bottani syndrome |
| | Trypanosomiasis, east-African |
| | Trypanosomiasis, west African |
| | Tsukahara Azuno Kajii syndrome |
| | Tuberous Sclerosis, type 1 |
| | Tuberous Sclerosis, type 2 |
| | Tunglang Savage Bellman syndrome |
| | Twin twin transfusion syndrome |
| | Tyrosine-oxidase temporary deficiency |
| |