| Hormonal disorderGoiterous cretinism(One of the many different types of hypothyroidism) | Iodotyrosine dehalogenase | Dwarfism, mental retardation, goiter, coarse skin and facial features. | |
| Blood coagulation disorderHaemophilia A | Factor VIII | Spontaneous bleeding, especially into large joints and muscles, hematoma, chronic arthritis, can be fatal if left untreated. | Supplementation with Factor VIII |
| Connective tissue disorder Osteogenesis imperfecta, type I | Procollagen type I | Osteoporosis, bone fractures, blue sclera (outer layer of eyeball), hearing loss. | No satisfactory treatment available |
| Connective tissue disorder Marfan Syndrome | Fibrillin | Long, thin fingers and limbs, chest deformity, loose joints, curved spine, displaced lens, cardiovascular problems, including tendency to aortic rupture. | Surgical therapy for correction for cardiac defects |
