ICD10 code of Hypophosphatasia and ICD9 code

The medical billing code for Hypophosphatasia is ICD-10-CM code E83.31, which specifically designates "Hypophosphatasia." In the older ICD-9-CM classification system, Hypophosphatasia was categorized under code 275.49, representing "Other disorders of calcium metabolism."

What is Hypophosphatasia and how is it classified?

Hypophosphatasia (HPP) is a rare, inherited metabolic disorder characterized by defective mineralization of bone and teeth. It is caused by loss-of-function mutations in the ALPL gene, which encodes the tissue-nonspecific alkaline phosphatase (TNSALP) enzyme. Because this enzyme is essential for bone mineralization, its deficiency leads to a wide spectrum of clinical manifestations, ranging from severe neonatal forms with respiratory failure to milder adult forms presenting with premature tooth loss or stress fractures. Recognizing Hypophosphatasia early is critical, as clinical severity varies significantly depending on the age of onset and the specific genetic variant involved.

How is Hypophosphatasia diagnosed?

Diagnosis of Hypophosphatasia relies on a combination of biochemical testing and genetic confirmation. The hallmark laboratory finding is a low serum alkaline phosphatase (ALP) level, adjusted for age and sex. Physicians may also look for elevated levels of substrates such as pyridoxal 5'-phosphate (PLP), phosphoethanolamine (PEA), and inorganic pyrophosphate (PPi). Clinical assessment often involves skeletal surveys to identify rickets-like changes or osteomalacia. Genetic testing for ALPL mutations is the gold standard for confirmation and family counseling.

What are the primary clinical features of Hypophosphatasia?

The presentation of Hypophosphatasia is highly variable, often categorized by the age at which symptoms first appear. Common clinical markers include:

• Dental manifestations: Premature loss of primary teeth (often before age 5) with intact roots, due to cementum hypoplasia.


• Skeletal abnormalities: Rickets in infants and children, or osteomalacia (softening of bones) in adults, leading to bone pain and recurrent fractures.


• Respiratory issues: Severe neonatal cases often involve life-threatening respiratory failure due to hypoplastic, poorly mineralized ribs.


• Systemic effects: Hypercalcemia and hypercalciuria, which may lead to nephrocalcinosis (calcium deposits in the kidneys).


• Muscle weakness: Proximal muscle weakness and gait abnormalities are frequently reported by our community members.

Is Hypophosphatasia hereditary?

Yes, Hypophosphatasia is a genetic condition. The inheritance pattern depends on the specific mutation: it can be inherited in an autosomal recessive manner (often more severe) or an autosomal dominant manner (often milder). Genetic counseling is strongly recommended for families affected by Hypophosphatasia to understand the recurrence risk for future pregnancies and to identify asymptomatic carriers within the family tree.

Next steps

• Consult a metabolic bone specialist, endocrinologist, or geneticist to manage the complexities of Hypophosphatasia.


• Request a baseline serum ALP level test if you suspect symptoms align with this diagnosis.


• Connect with the 9 community members on DiseaseMaps.org who are navigating life with Hypophosphatasia to share experiences and coping strategies.


• Monitor for dental health by seeing a pediatric dentist or periodontist familiar with metabolic bone disorders.

Medical disclaimer: This information is for educational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

• Orphanet: Hypophosphatasia (ORPHA:418)


• NIH Genetic and Rare Diseases Information Center (GARD): Hypophosphatasia


• OMIM (Online Mendelian Inheritance in Man): Hypophosphatasia (#146300, #241500, #241510)


• The Hypophosphatasia Foundation (hpfusa.org)