Genetic Link Found Between Hip Dysplasia and Osteoarthritis
A multinational research team has identified shared genetic variations between developmental dysplasia of the hip (DDH) and hip osteoarthritis (OA). The findings, published online in the journal Bone Research on March 31, 2026, point to possible common mechanisms behind both conditions.
Key Study Details
The genome-wide association study (GWAS) analyzed tissue samples from Japan and the United Kingdom, followed by a meta-analysis on approximately 350,000 additional samples from Europe.
The research identified variations in three specific genetic loci common to both DDH and hip OA, highlighting a direct genetic link between the developmental disorder and the degenerative joint disease.
Major Findings
The study pinpointed three key genetic loci shared by both conditions:
- COL11A2: Codes for a protein chain in collagen, a major structural component of cartilage.
- CALN1: Encodes a calcium-binding protein.
- TRPM7: Regulates magnesium and calcium ion levels and is known to affect bone regeneration.
Furthermore, the analysis revealed nine loci associated with DDH and its subtypes. A crucial discovery was that the genetic signals for hip dysplasia without dislocation were distinct from those for hip dislocation.
Dr. Ryosuke Yamaguchi noted: "In total, nine loci were identified for DDH and its subtypes, with hip dysplasia without dislocation showing distinct genetic signals from hip dislocation... these suggest that while polygenic architecture is largely shared between the two subsets of DDH, there are genetic differences in a part of specific genetic loci."
The study also found that several genes affecting bone cell growth and bone remodeling were associated with DDH—genes already known to be involved in the progression of hip OA. Additionally, variations in non-coding DNA regions were similar between the two disorders, suggesting that altered gene regulation may be a common underlying factor.
Background on the Conditions
Developmental dysplasia of the hip (DDH) is a polygenetic disorder where the hip joint does not form properly, significantly increasing the risk of developing hip osteoarthritis later in life. Symptoms can appear early after birth and range from mild instability to total hip dislocation.
Family history is a major risk factor; individuals with a parent or sibling with DDH are reportedly 12 times more likely to have the disorder. Recent studies indicate about 70% of Japanese patients with hip OA have some form of DDH, underscoring the strong connection between the two conditions.
Implications and Future Research
The findings open new avenues for understanding the biological pathways of DDH and identifying potential targets for therapies aimed at hip osteoarthritis.
Understanding the genetic basis of DDH may eventually enable the development of targeted treatments for its subtypes, potentially slowing the progression to hip OA and improving long-term patient quality of life.
Dr. Chikashi Terao emphasized the path forward: "These findings underscore the need for future DDH-specific multi-omics studies, integrating genetic data with tissue-specific gene expression, chromatin accessibility, and spatial chromatin structure, especially in chondrocytes, to fully elucidate the functional mechanisms underlying this complex disorder."