- Haim-Munk syndrome
- Hair loss syndromes
- Hallermann-Streiff syndrome
- Hand-foot-uterus syndrome
- Harlequin fetus
- Hemihypertrophy (Hemihyperplasia)
- Hemochromatosis
- Hemolytic-uremic syndrome
- Hemophilia
- Hereditary angioneurotic edema
- Hereditary colorectal cancer
- Hereditary desmoid disease
- Hereditary hearing loss and deafness
- Hereditary multiple exostoses
- Hereditary pancreatitis
- Hereditary spastic paraplegia
- Hermansky-Pudlak syndrome
- Hermaphroditism
- Hirschsprung's disease
- Holoprosencephaly
- Holt-Oram syndrome
- Homocystinuria
- Human Genome Project
- Hunter syndrome
- Huntington disease
- Hurler syndrome
- Hydrocephalus
- Hydrolethalus syndrome
- Hydrops fetalis
- Hyperlipoproteinemia
