Achondrogenesis type IA (ACG1A) is a very rare skeletal condition that affects bone development. It is a type of skeletal dysplasia that leads to dwarfism, with extremely short limbs, a narrow chest, and a set of skeletal features that can be observed at birth. People with this condition often have short ribs that may fracture easily and soft skull bones, reflecting unique and challenging aspects of their bone structure. This condition is recognized by its distinctive features in the cartilage and the way the bones form. Its severity places it among rare and life-threatening conditions, making it important for families and caregivers to understand that it affects multiple parts of the skeletal system. The condition is known by several names including Houston-Harris achondrogenesis and achondrogenesis type 1A.

Common signs of achondrogenesis type IA include dwarfism, extremely short limbs, a narrow chest, and ribs that are more prone to fracture. Other features include soft skull bones and differences in cartilage structure.

Achondrogenesis type IA is linked to changes in the TRIP11 gene. This genetic mutation affects the normal development of cartilage and bone, leading to the characteristics seen in this condition. This genetic issue is a key factor in the development of the disorder. Associated genes include TRIP11.