| Diagnosis | Omim Number | Sample Count |
| D-GLYCERICACIDEMIA | 220120 | 1 |
| DANDY-WALKER MALFORMATION WITH MENTAL RETARDATION, BASAL GANGLIA DISEASE, AND SEIZURES | 304340 | 21 |
| DE SANCTIS-CACCHIONE SYNDROME | 278800 | 6 |
| DEAFNESS WITH DNA REPAIR DEFICIENCY | | 4 |
| DEAFNESS, AUTOSOMAL RECESSIVE 1A; DFNB1A | 220290 | 5 |
| DEAFNESS, AUTOSOMAL RECESSIVE 28; DFNB28 | 609823 | 3 |
| DEAFNESS, AUTOSOMAL RECESSIVE 49; DFNB49 | 610153 | 10 |
| DELETED IN AZOOSPERMIA; DAZ | 400003 | 4 |
| DELTA-BETA THALASSEMIA | 141749 | 2 |
| DENTATORUBRAL-PALLIDOLUYSIAN ATROPHY; DRPLA | 125370 | 3 |
| DENYS-DRASH SYNDROME; DDS | 194080 | 1 |
| DEVELOPMENTAL AND EPILEPTIC ENCEPHALOPATHY 42; DEE42 | | 6 |
| DEVELOPMENTAL AND EPILEPTIC ENCEPHALOPATHY 66; DEE66 | | 8 |
| DEVELOPMENTAL AND EPILEPTIC ENCEPHALOPATHY 74; DEE74 | | 2 |
| DEVELOPMENTAL AND EPILEPTIC ENCEPHALOPATHY 85 WITH OR WITHOUT MIDLINE BRAIN DEFECTS; DEE85 | | 1 |
| DIABETES MELLITUS, JUVENILE-ONSET INSULIN-DEPENDENT; IDDM | 222100 | 75 |
| DIABETES MELLITUS: MATURITY ONSET DIABETES - 222100 OR 125850 | | 3 |
| DIAPHYSEAL MEDULLARY STENOSIS WITH MALIGNANT FIBROUS HISTIOCYTOMA | 112250 | 10 |
| DIGEORGE SYNDROME; DGS | 188400 | 11 |
| DISACCHARIDE INTOLERANCE I | 222900 | 1 |
| DOPAMINE TRANSPORTER DEFICIENCY SYNDROME; DTDS | | 1 |
| DUBOWITZ SYNDROME | 223370 | 1 |
| DYGGVE-MELCHIOR-CLAUSEN DISEASE | 223800 | 4 |
| DYSCHONDROSTEOSIS | 127300 | 1 |
| DYSKERATOSIS CONGENITA, X-LINKED; DKC | 305000 | 8 |
| DYSTONIA 1, TORSION; DYT1 | 128100 | 7 |
| DYSTONIA MUSCULORUM DEFORMANS 2; DYT2 | 224500 | 7 |
| DYSTONIA MUSCULORUM DEFORMANS: TYPE UNKNOWN | | 10 |
| DYSTROPHIA MYOTONICA 1; DM1 | 160900 | 54 |