What is infantile hypophosphatasia?
What is infantile hypophosphatasia?
Disease definition. A rare, severe, genetic form of hypophosphatasia (HPP) characterized by infantile rickets without elevated serum alkaline phosphatase (ALP) activity and a wide range of clinical manifestations due to hypomineralization.
What are the symptoms of hypophosphatasia?
Signs and symptoms may include poor feeding and respiratory problems in infancy; short stature ; weak and soft bones; short limbs; other skeletal abnormalities; and hypercalcemia. Complications can be life-threatening. The mildest form of the condition, called odontohypophosphatasia, only affects the teeth.
What is hypophosphatasia HPP?
Hypophosphatasia (HPP) is an inborn error of metabolism with highly variable clinical severity caused by loss-of-function mutations in the gene encoding tissue nonspecific alkaline phosphatase (TNSALP). The prevalence of the severe form is estimated to be between 1/100,000 and 1/300,000.
How is hypophosphatasia passed down?
How is hypophosphatasia inherited? Perinatal (onset before birth) and infantile hypophosphatasia (HPP) are inherited in an autosomal recessive manner. This means that to be affected, a person must have a mutation in both copies of the responsible gene (ALPL) in each cell .
Is hypophosphatasia a disability?
Hypophosphatasia (perinatal and infantile onset types) is a disabling condition on the Compassionate Allowance List, which qualifies an individual for an expedited approval process.
Who is affected by hypophosphatasia?
Severe forms of hypophosphatasia affect an estimated 1 in 100,000 newborns. Milder cases, such as those that appear in childhood or adulthood, probably occur more frequently. Hypophosphatasia has been reported worldwide in people of various ethnic backgrounds.
What is the treatment for hypophosphatasia?
Nonsteroidal anti-inflammatory drugs (NSAIDs) to treat bone and joint pain. Vitamin B6 to help to control seizures in severely affected infants. Regular dental care beginning early on. Physical and occupational therapy.
How is hypophosphatasia diagnosed?
HPP is diagnosed by identifying its symptoms and complications beginning with a detailed patient history. HPP signs are revealed by a thorough clinical examination, and supported by routine x-rays and various laboratory tests including biochemical studies.
Can low vitamin D cause low alkaline phosphatase?
Thus, vitamin D deficiency is usually accompanied by normal blood levels for calcium and phosphorus, high-normal or elevated levels of PTH, normal to elevated levels of total alkaline phosphatase, a low 24-hour urine calcium excretion rate, and low levels of total 25(OH)D.
What type of doctor treats hypophosphatasia?
Patients may initially present to orthopedists, neurologists, nephrologists, neonatologists, pulmonologists, dentists, endocrinologists, rheumatologists and others before an accurate diagnosis is obtained, making it important for many specialists to become familiar with key hypophosphatasia warning signs and …
How does hypophosphatasia affect the body?
Hypophosphatasia weakens and softens the bones, causing skeletal abnormalities similar to another childhood bone disorder called rickets . Affected infants are born with short limbs, an abnormally shaped chest, and soft skull bones.
How do you treat hypophosphatasia?
Treatment and Medication Options for Hypophosphatasia
- Nonsteroidal anti-inflammatory drugs (NSAIDs) to treat bone and joint pain.
- Vitamin B6 to help to control seizures in severely affected infants.
- Regular dental care beginning early on.
- Physical and occupational therapy.
What causes hypophosphatasia to develop in children?
The forms of hypophosphatasia that develop during childhood are generally more mild than those that appear in infancy. Childhood hypophosphatasia is caused by changes (mutations) in the ALPL gene and can be inherited in an autosomal dominant or autosomal recessive manner.
How does hypophosphatasia cause short limbs and Soft Skull?
Hypophosphatasia weakens and softens the bones, causing skeletal abnormalities similar to another childhood bone disorder called rickets. Affected infants are born with short limbs, an abnormally shaped chest, and soft skull bones.
When do you know if you have hypophosphatasia?
The skeleton is hypomineralized, which is readily identified on X-ray. This form of HPP is almost universally fatal shortly after birth. Infantile HPP is diagnosed by 6 months of age. Characteristic changes of rickets are seen on X-ray, and fractures are often present.
Is the genetic inheritance of hypophosphatasia autosomal recessive?
Genetic inheritance is autosomal recessive for the perinatal and infantile forms but either autosomal recessive or autosomal dominant in the milder forms. The prevalence of hypophosphatasia is not known; one study estimated the live birth incidence of severe forms to be 1:100,000.