What is hypophosphatasia?
Hypophosphatasia is a condition caused by the body not having enough of a specific enzyme called tissue-nonspecific alkaline phosphatase (TNSALP), which is important for forming healthy bones and teeth. Signs and symptoms of this condition include soft, abnormally shaped bones and very high levels of calcium in the blood. The severity of hypophosphatasia varies, as does the age at which symptoms appear. The most severe forms are present at birth, while the least severe forms may not show signs until adulthood.
How common is hypophosphatasia?
Hypophosphatasia affects at least 1 in every 100,000 babies born in the United States each year.
What can be done for hypophosphatasia?
Identifying this condition early can lead to reduced symptoms and an improved quality of life. Certain symptoms of this condition require ongoing attention and care by a team of medical specialists. There is also a form of treatment that replaces the missing TNSALP enzyme - this is called enzyme replacement therapy (ERT). While ERT isn’t a complete cure for hypophosphatasia, it can make many of the symptoms less severe.
How is hypophosphatasia inherited?
Hypophosphatasia is caused by changes in the ALPL gene. It is a recessive inherited condition, which means that a person must inherit two altered copies of the ALPL gene, one from each parent, in order to have the disease. People who have only one copy of the altered ALPL gene are called carriers, and are not expected to have symptoms of the condition. If a baby is identified as a carrier for hypophosphatasia through Eli screening, genetic counseling and additional testing in the parents is recommended.