With the help of four generations of a 72-member family from Utah, a team comprising researchers from Thomas Jefferson University and the University of Utah has gained better understanding of the role genetics plays in developing hip dysplasia. The findings of their study pave the way for creating a genetic test that can deliver accurate identification of developmental dysplasia of the hip (DDH) in newborns. This will in turn allow early intervention to ensure normal development.
DDH affects one out of 1,000 newborn babies and, while the most severe forms are apparent right from the start, mild instances often remain undetected. They are the main reason for premature hip joint degeneration among people aged 20 to 40. Since the acetabulum does not form completely around the femur head, people with DDH suffer from dislocation of the femur, impaired joint function and accelerated wear of the articular cartilage, which leads to arthritis.
The examination of the family members revealed that 11 of them exhibited at least three signs of DDH and there was no doubt as to their condition. In 13 family members the researchers detected one or two signs and the diagnosis in those cases was questionable. The DNA analysis revealed a genetic mutation that was present in all affected individuals. This variant constitutes a mutation on chromosome 3 in a chemokine receptor that plays the role of a receptor for a chemical messenger, potentially affecting the development of cartilage-forming cells by delaying it. Even people with fewer DDH signs were found to carry the disease variant.