Matsuo Kumihiro, Mukai Tokuo, Furuya Akiko, Suzuki Shigeru, Tanahashi Yusuke, Azuma Hiroshi
Department of Pediatrics, Asahikawa Medical College, Asahikawa, Japan.
Clin Pediatr Endocrinol. 2013 Oct;22(4):73-6. doi: 10.1292/cpe.22.73. Epub 2013 Oct 26.
Elevated serum alkaline phosphatase (ALP) is a screening marker for the diagnosis of vitamin D deficiency, which may fail to be diagnosed if serum ALP is not elevated. Here, we describe a case of vitamin D deficiency without elevation of serum ALP. A 1-year-old Japanese girl was referred to our hospital for the evaluation of genu varum. Her serum intact PTH level was elevated, while her serum ALP level was normal. Furthermore, her serum 25-hydroxyvitamin D level was reduced, and her urine phosphoethanolamine (PEA) level was mildly elevated. ALPL gene analysis revealed she was a heterozygous carrier of hypophosphatasia (c.1559delT). Serum intact PTH and urine PEA evaluations were helpful for diagnosing vitamin D deficiency and hypophosphatasia carrier status, respectively. Therefore, the possibility of vitamin D deficiency without elevation of serum ALP should be considered.
血清碱性磷酸酶（ALP）升高是诊断维生素D缺乏的一项筛查指标，如果血清ALP未升高，维生素D缺乏可能无法被诊断出来。在此，我们描述一例血清ALP未升高的维生素D缺乏病例。一名1岁日本女孩因膝内翻被转诊至我院。她的血清全段甲状旁腺激素（PTH）水平升高，而血清ALP水平正常。此外，她的血清25-羟维生素D水平降低，尿磷酸乙醇胺（PEA）水平轻度升高。ALPL基因分析显示她是低磷酸酯酶症的杂合子携带者（c.1559delT）。血清全段PTH和尿PEA评估分别有助于诊断维生素D缺乏和低磷酸酯酶症携带者状态。因此，应考虑血清ALP未升高的维生素D缺乏的可能性。
