Despite its importance as a key parameter of child health and development, growth velocity is difficult to determine in real time because skeletal growth is slow and clinical tools to accurately detect very small increments of growth do not exist. We report discovery of a marker for skeletal growth in infants and children. The intact trimeric noncollagenous 1 (NC1) domain of type X collagen, the marker we designated as CXM for Collagen X Marker, is a degradation by-product of endochondral ossification that is released into the circulation in proportion to overall growth plate activity. This marker corresponds to the rate of linear bone growth at time of measurement. Serum concentrations of CXM plotted against age show a pattern similar to well-established height growth velocity curves and correlate with height growth velocity calculated from incremental height measurements in this study. The CXM marker is stable once collected and can be accurately assayed in serum, plasma, and dried blood spots. CXM testing may be useful for monitoring growth in the pediatric population, especially responses of infants and children with genetic and acquired growth disorders to interventions that target the underlying growth disturbances. The utility of CXM may potentially extend to managing other conditions such as fracture healing, scoliosis, arthritis, or cancer.

尽管它是儿童健康和发育的关键参数，但其生长速度很难实时确定，因为骨骼生长缓慢且不存在用于精确检测很小的增长增量的临床工具。我们报告发现婴儿和儿童骨骼生长的标志物。X型胶原的完整三聚体非胶原1（NC1）域（我们称为胶原X标记的CXM标记）是软骨内骨化的降解副产物，与总生长板活性成比例地释放到循环中。该标记对应于测量时线性骨生长的速率。根据年龄绘制的CXM血清浓度显示出与成熟的身高生长速度曲线相似的模式，并且与通过这项研究中的增量身高测量值计算得出的身高生长速度相关。CXM标记物一经收集便稳定，可在血清，血浆和干血斑中进行准确测定。CXM测试可能有助于监测儿科人群的生长情况，特别是患有遗传性和后天性生长障碍的婴儿和儿童对针对潜在生长障碍的干预措施的反应。CXM的用途可能会扩展到管理其他情况，例如骨折愈合，脊柱侧弯，关节炎或癌症。CXM测试可能有助于监测儿科人群的生长情况，尤其是对患有遗传性和后天性生长障碍的婴儿和儿童对针对潜在生长障碍的干预措施的反应。CXM的用途可能会扩展到管理其他情况，例如骨折愈合，脊柱侧弯，关节炎或癌症。CXM测试可能有助于监测儿科人群的生长情况，特别是患有遗传性和后天性生长障碍的婴儿和儿童对针对潜在生长障碍的干预措施的反应。CXM的用途可能会扩展到管理其他情况，例如骨折愈合，脊柱侧弯，关节炎或癌症。