Tiana inherited Brittle Bone Disease from her mum
Although most genetic disorders involve inheriting a faulty gene from both parents, sometimes conditions are caused by inheriting a gene from just one parent.
Huntington’s Disease and Achondroplasia (dwarfism) are examples of conditions which follow a dominant pattern of inheritance.
This means the effects of the altered gene override the working copy.
Osteogenesis Imperfecta or Brittle Bone Disease is another dominant condition. Watch Tiana and Star's story about living with Brittle Bone Disease »
Dominant inheritance
Photo: US National Library of Medicine