| Diagnosis | Omim Number | Sample Count |
| HARTNUP DISORDER | 234500 | 2 |
| HELSMOORTEL-VAN DER AA SYNDROME; HVDAS | | 4 |
| HEMI DYSTONIA | | 14 |
| HEMOCHROMATOSIS, NEONATAL | 231100 | 10 |
| HEMOCHROMATOSIS; HFE | 235200 | 33 |
| HEMOGLOBIN F, HEREDITARY PERSISTENCE OF | 141749 | 12 |
| HEMOGLOBIN, GAMMA A; HBG1 | 142200 | 1 |
| HEMOGLOBIN--ALPHA LOCUS 1; HBA1 | 141800 | 5 |
| HEMOGLOBIN--BETA LOCUS; HBB | 141900 | 18 |
| HEMOGLOBIN--DELTA LOCUS; HBD | 142000 | 3 |
| HEMOPHILIA B; HEMB | 306900 | 3 |
| HEREDITARY HEMORRHAGIC TELANGIECTASIA | 187300 | 1579 |
| HERMANSKY-PUDLAK SYNDROME 2; HPS2 | 608233 | 1 |
| HERMANSKY-PUDLAK SYNDROME 6; HPS6 | | 1 |
| HERMANSKY-PUDLAK SYNDROME; HPS | 203300 | 4 |
| HLA HISTOCOMPATIBILITY TYPE: 142800 THROUGH 142860 & 142880 | 142800 | 41 |
| HLA HISTOCOMPATIBILITY TYPE: 142800 THROUGH 142860 & 142880 | 142860 | 41 |
| HLA HISTOCOMPATIBILITY TYPE: 142800 THROUGH 142860 & 142880 | 142880 | 41 |
| HOLOCARBOXYLASE SYNTHETASE DEFICIENCY | 253270 | 6 |
| HOLOPROSENCEPHALY | | 3 |
| HOLOPROSENCEPHALY 2; HPE2 | 157170 | 1 |
| HOLOPROSENCEPHALY 2; HPE2 | 236100 | 1 |
| HOLOPROSENCEPHALY 3; HPE3 | 142945 | 2 |
| HOLOPROSENCEPHALY 4; HPE4 | 142946 | 8 |
| HOLT-ORAM SYNDROME; HOS | 142900 | 2 |
| HOMOCYSTINURIA | 236200 | 46 |
| HOMOCYSTINURIA DUE TO DEFICIENCY OF N(5,10)-METHYLENETETRAHYDROFOLATE REDUCTASE ACTIVITY | 236250 | 4 |
| HOMOCYSTINURIA-MEGALOBLASTIC ANEMIA, CBLG COMPLEMENTATION TYPE; HMAG | 250940 | 3 |
| HUNTINGTON DISEASE; HD | 143100 | 152 |
| HUNTINGTON DISEASE; HD | 143100 | 219 |
| HURLER SYNDROME | 607014 | 17 |
| HURLER-SCHEIE SYNDROME | 607015 | 12 |
| HUTCHINSON-GILFORD PROGERIA SYNDROME; HGPS | 176670 | 52 |
| HYDATIDIFORM MOLE | 231090 | 1 |
| HYPER IGM, TYPE UNKNOWN | | 1 |
| HYPERCHOLESTEROLEMIA, AUTOSOMAL RECESSIVE; ARH | 603813 | 5 |
| HYPERCHOLESTEROLEMIA, FAMILIAL; FHC | 143890 | 27 |
| HYPERGLYCEROLEMIA | 307030 | 17 |
| HYPERGLYCINEMIA, ISOLATED NONKETOTIC, TYPE I | 238300 | 10 |
| HYPERGLYCINEMIA, ISOLATED NONKETOTIC, TYPE I | 238310 | 10 |
| HYPERLIPIDEMIA, FAMILIAL COMBINED | 144250 | 1 |
| HYPERLIPOPROTEINEMIA, TYPE I | 238600 | 1 |
| HYPERLYSINEMIA | 238700 | 1 |
| HYPERPIPECOLATEMIA | 239400 | 1 |
| HYPERTHYROXINEMIA, FAMILIAL DYSALBUMINEMIC; FDAH | | 1 |
| HYPOCHONDROPLASIA; HCH | 146000 | 1 |
| HYPOMELANOSIS OF ITO; HMI | 300337 | 2 |
| HYPOPARATHYROIDISM-RETARDATION-DYSMORPHISM SYNDROME; HRD; SANJAD-SAKATI SYNDROME | 241410 | 1 |
| HYPOPHOSPHATASIA, INFANTILE | 241500 | 4 |
| HYPOPHOSPHATASIA; PHOSPHOETHANOLAMINURIA - 241500 OR 241510 | 241510 | 24 |
| HYPOPHOSPHATASIA; PHOSPHOETHANOLAMINURIA - 241500 OR 241510 | 241500 | 24 |
| HYPOPHOSPHATEMIC RICKETS, X-LINKED DOMINANT | 307800 | 2 |
| HYPOPLASTIC LEFT HEART SYNDROME | 241550 | 1 |