Which disorder is associated with blue discoloration of the sclera?

The disorder associated with blue discoloration of the sclera is Osteogenesis imperfecta. This condition, often referred to as "brittle bone disease," is a genetic disorder characterized by fragile bones that break easily, often with little or no apparent cause.

The blue sclera in Osteogenesis imperfecta is due to the reduced amount of collagen in the connective tissue and the underlying thinness of the scleral tissue. As a result, the underlying vascular structures become more visible through the translucent sclera, leading to a blue appearance. This clinical finding can serve as a useful diagnostic clue for healthcare providers when assessing a patient who may have Osteogenesis imperfecta.

While other conditions listed may have various clinical manifestations, they do not typically present with the distinctive blue sclera associated with this disorder. For instance, Marfan syndrome is more related to connective tissue abnormalities and tall stature, achondroplasia primarily affects bone growth resulting in dwarfism, and Down syndrome is associated with specific physical traits and developmental delays, but none of these disorders are known for causing blue discoloration of the sclera.