Linkage Mapping and Whole Exome Sequencing Identify a Shared Variant in CX3CR1 in a Large Multi-Generation Family

Developmental dysplasia of the hip (DDH) is a crippling condition that affects children and adults, with an average incidence of 1–1.5 cases per 1000 live births. It results in disabling arthritis of the hip in up to 60% patients in the 20–40 year age group. There is no accurate diagnostic test available for newborns. The purpose of our study is to develop a sensitive and specific genetic test for DDH by identifying causative mutations. Linkage analysis and whole exome sequencing of 4 severely affected individuals of a 4 generation 71 member family was performed. The damaging rs3732378 variant in the CX3CR1 chemokine receptor was shared by all affected family members and by 15% of 28 sporadic dysplastics.