Fig. 1

The 2-dimensional (2D) CT and sequencing results of a 43 year old woman with OPLL in the cervical spine. a The 2D CT showed that the patient had OPLL (C2–C3, C4-C5, C6, and C7 mixed type). b The direct sequencing results of the PCR products showing the A/C heterozygous mutation of 4A > C polymorphism in BMPR-IA gene. A allele: green line; T allele: red line; C allele: blue line; G allele: black line