Infantile loss of teeth: odontohypophosphatasia or childhood hypophosphatasia

HALİLOĞLU B., GÜRAN T., Atay Z., ABALI S., Mornet E., BEREKET A., ...More

EUROPEAN JOURNAL OF PEDIATRICS, vol.172, no.6, pp.851-853, 2013 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 172 Issue: 6
  • Publication Date: 2013
  • Doi Number: 10.1007/s00431-012-1868-4
  • Journal Name: EUROPEAN JOURNAL OF PEDIATRICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.851-853
  • Keywords: Hypophosphatasia, Tooth, Odontohypophosphatasia, Infantile teeth loss, ALKALINE-PHOSPHATASE, PHENOTYPE, GENOTYPE
  • Acibadem Mehmet Ali Aydinlar University Affiliated: Yes

Abstract

Hypophosphatasia is a hereditary disorder characterized by a deficiency of serum and bone alkaline phosphatase (ALP) activity and defective skeletal mineralization. It is caused by a loss of function mutations in the tissue nonspecific ALP gene (TNSALP) encoding the tissue nonspecific alkaline phosphatase. A 4-year-and-8-month-old girl presented with premature exfoliation of the anterior incisors and canines. Very low ALP level (27 IU/ml) suggested the diagnosis of hypophosphatasia, which was supported by an elevated urine phosphoethanolamine/Cr of 84 mu mol/mmol (reference range, < 25 mu mol/mmol) and serum pyridoxal-5'-phosphate of 393 mu g/L (reference range, 3.6-18 mu g/L). The phenotype of the patient was subsequently classified as mild childhood hypophosphatasia. TNSALP gene sequencing revealed the homozygous c.382 G > A (p.V128M) mutation. This mutation was previously observed in a series of patients with severe hypophosphatasia, pointing out the possible role of other genetic or environmental factors in the modulation of the hypophosphatasia phenotype.