What Your Test Results Mean:

Some individuals with one copy will show symptoms of hypophosphatasia while others will remain asymptomatic. Whether you have symptoms of the disease or not, you are at an increased risk to have a child with hypophosphotasia. Carrier testing of your partner is recommended in addition to consultation with a genetic counselor.

Disease Explained:

Hypophosphatasia is an inherited disorder that is characterized by weak and soft bones that result in skeletal abnormalities, short limbs, abnormally shaped chest, poor feeding, failure to gain weight, respiratory problems, hypercalcemia, and kidney problems. These problems can be life-threatening. Symptoms appear anywhere from before birth to adulthood, depending on the severity of the disease. Adult-onset hypophosphatasia is characterized by softening of the bones. In adults, recurrent fractures in the foot and thigh bones can lead to chronic pain. Affected children experience short stature with bowed legs or knock knees, enlarged wrist and ankle joints, and an abnormal skull shape. Currently, there is no approved therapy for hypophosphatasia. Current management of the disease involves relieving symptoms, maintaining calcium balance and using surgical interventions when needed.

How the Genetics Works:

Hypophosphatasia is a genetic disorder caused by pathogenic variants in the ALPL gene. In general, individuals have two copies of the ALPL gene. Some individuals with one variant in the ALPL gene may have mild symptoms of the disease; however, most affected individuals have two variants in their ALPL genes. Risk for an individual with one mutation in the ALPL gene is up to 50% for having a child with the disorder.