How many types of osteogenesis imperfecta are there?

There are 8 types: Dominantly Inherited Type I:Mildest form ~ 50% of total. Type II:Most severe form. High mortality rate Type III:Most severe type who survives neonatal period. Type IV: Moderate-severe growth retardation Type V: Moderate in severity. Hypertrophic calluses Type VI:Rare.Similar symptoms to OI Type IV Resessively inherited Types VII and VIII Type VII resembles IV and II Type VIII similar to II, III