Which feature is associated with Type 2 Osteogenesis Imperfecta?

Type 2 Osteogenesis Imperfecta (OI) is classified as the most severe form of the condition and is often abbreviated as "lethal OI." This type is characterized by multiple fractures that occur in utero and at birth, leading to significant complications that can be fatal in the perinatal period. Infants with Type 2 OI may have pronounced skeletal deformities and often present with a very small body size, short limbs, and a narrow chest—features that contribute to respiratory distress and a significant risk of mortality shortly after birth.

The association of Type 2 OI with lethal outcomes distinguishes it from other types of OI that may present with varying degrees of severity and features, such as normal or blue sclerae. In particular, blue sclerae is a characteristic feature of some other types of OI but is not associated with Type 2, as the scleral appearance can vary based on the specific type and severity of the condition. Hence, the presence of normal sclerae or blue sclerae does not apply to Type 2 OI, reinforcing its classification as lethal due to its severe manifestations and high mortality risk.