| Diagnosis | Omim Number | Sample Count |
| ICHTHYOSIFORM ERYTHRODERMA, CONGENITAL, NONBULLOUS, 1; NCIE1 | 242100 | 1 |
| ICHTHYOSIS CONGENITA, HARLEQUIN FETUS TYPE | 242500 | 3 |
| ICHTHYOSIS, X-LINKED | 308100 | 14 |
| ICHTHYOSIS, X-LINKED, WITHOUT STEROID SULFATASE DEFICIENCY | 300001 | 11 |
| IMMUNODEFICIENCY 96; IMD96 | | 2 |
| IMMUNODEFICIENCY WITH HYPER-IGM, TYPE 2 | 605258 | 2 |
| IMMUNODEFICIENCY-CENTROMERIC INSTABILITY-FACIAL ANOMALIES SYNDROME | 242860 | 4 |
| IMMUNOOSSEOUS DYSPLASIA | 242900 | 1 |
| INCLUSION BODY MYOPATHY 2, AUTOSOMAL RECESSIVE; IBM2 | | 1 |
| INCLUSION BODY MYOPATHY WITH EARLY-ONSET PAGET DISEASE AND FRONTOTEMPORAL DEMENTIA; IBMPFD | 167320 | 78 |
| INCLUSION BODY MYOSITIS | 147421 | 1 |
| INCONTINENTIA PIGMENTI; IP | 308300 | 5 |
| INOSINE TRIPHOSPHATASE DEFICIENCY | | 2 |
| INTELLECTUAL DEVELOPMENTAL DISORDER WITH HYPOTONIA, IMPAIRED SPEECH, AND DYSMORPHIC FACIES; IDDHISD | | 1 |
| INTELLECTUAL DEVELOPMENTAL DISORDER, AUTOSOMAL DOMINANT 45; MRD45 | | 2 |
| INTELLECTUAL DEVELOPMENTAL DISORDER, X-LINKED, SYNDROMIC, WITH PIGMENTARY MOSAICISM AND COARSE FACIES; MRXSPF | | 1 |
| ISOBUTYRYL-COA DEHYDROGENASE DEFICIENCY | 611283 | 1 |
| ISOVALERICACIDEMIA; IVA | 243500 | 3 |