What is HPP?

HPP AND ALP SIGNS AND SYMPTOMS HOW IT’S DIAGNOSED SPECIALISTS WHO CAN HELP

RAY, HPP star

What is
hypophosphatasia (HPP)?

Hypophosphatasia (hypo-fahs-fuh-TAY-shuh), or HPP, is a rare, inherited disease that affects the bones and other parts of the body.

HPP AND ALP

People with HPP have a mutation in the ALPL gene, which may cause missing or not enough alkaline phosphatase (ALP) enzyme. This means that people with HPP have ALP levels lower than the healthy normal for their age and sex. When this is the case, the body has trouble making healthy bones. Low ALP levels can make bones soft, weak, and deformed, and cause other symptoms of HPP.

Learn more about ALP and how STRENSIQ® (asfotase alfa) works to replace it.

All people have the ALPL gene, which makes an enzyme called ALP. The body needs ALP to form healthy bones.

HPP SIGNS AND SYMPTOMS

HPP looks different for every person. The condition can affect people of all ages and may vary in terms of severity of signs and symptoms—even in the same family. New symptoms can appear at any age. Symptoms can continue long-term, and they can worsen over time.

HPP can affect many different parts of the body. Early tooth loss, frequent bone injuries, and muscle weakness and pain are some examples of impact.

Use the skeletal graphic to explore more impacts of HPP.




Not an exhaustive list

SKULL AND BRAIN
TEETH
RIBS AND LUNGS
KIDNEYS
MUSCLES AND JOINTS
BONES
Human body
×

Skull and brain

  • Abnormally shaped head
  • Seizures in infants

Teeth

  • Early tooth loss

Ribs and lungs

  • Rib cage bones may not grow properly
  • Breathing complications that may be severe

Kidneys

  • Buildup of calcium

Muscles and joints

  • Muscle weakness and pain

Bones

  • Weak or brittle bones
  • Frequent bone injuries
  • Bowing of the legs

HPP Symptoms throughout a person’s life

Infants

  • Short limbs, abnormal chest or head shape, and soft skull bones
  • Life-threatening complications, such as pressure on the brain, seizures, and difficulty breathing
  • When left untreated, chances of survival are low for infants with HPP

Children and adolescents

  • Slow or stunted growth
  • Difficulty doing things their friends can do, from basic activities like walking, bending, or climbing stairs to high-energy activities like riding a bike or skating
  • Muscle pain, weakness, and fatigue that peers their age don’t experience

Adults

  • Continued difficulties that may have been experienced during childhood and adolescent activities
  • Daily challenges, such as trouble walking, running, standing from a sitting position, and picking things up
  • Severe muscle, joint, or bone pain that could limit activity

It is common for people of all ages with HPP to need some form of an assistive device to help them get around.

How A Doctor May Diagnose HPP

A person who shows signs and symptoms of HPP should talk to their doctor about taking a blood test to examine their ALP level. After a thorough exam and reviewing medical history, if blood test results reveal their ALP level is low for someone of their age and sex, a doctor may diagnose them with HPP.

HPP is often misdiagnosed. ALP can be low because of HPP, but it can also be low for other reasons. Because HPP is rare, not every doctor has the same amount of experience with the disease. Also, some of the symptoms of HPP can be symptoms for other, more common conditions.

It’s The combination of one or more HPP symptoms with persistently low ALP
levels that have no other explanation that can lead your doctor to diagnose HPP

Signs and symptoms on physical examination,
x-rays, or in patient history

Persistently low ALP
enzyme levels*‎‎

Signs and symptoms on physical examination,
x-rays, or in patient history

Persistently low ALP
enzyme levels*‎

Check with your doctor for the appropriate age- and sex-adjusted reference range.

The power of an
hpp diagnosis

After all those years, I finally
received my diagnosis, and I felt
vindicated and surprisingly happy.
I knew there was a
treatment, and I was excited to try it.”

Sheila, HPP STAR

Conditions that can look like HPP

Below are other diseases that may be more common and have shared symptoms with HPP.
Diseases in bold often have overlapping symptoms and therefore can be common misdiagnoses.

Weak bones

Rickets (nutritional rickets and X-linked hypophosphatemic rickets)
Osteopenia/osteoporosis
Osteogenesis imperfecta
Osteomalacia

Chronic pain and joint problems

Osteoarthritis/arthritis
Rheumatoid arthritis
Leukemia or bone cancer
Fibromyalgia
Pseudogout

Tooth loss

Gum disease
Dentinogenesis imperfecta

WHAT WAS YOUR HPP DIAGNOSIS JOURNEY LIKE?

SPECIALISTS WHO CAN HELP WITH HPP

When it comes to rare diseases, specialists are important. Specialists are trained to treat rare diseases and may better understand ways to manage symptoms.

If you believe you or someone you care for has HPP but has not been diagnosed, look for a specialist who may be familiar with HPP. Some specialists who may be able to help include:

genetics

Geneticists

Study the role that genes play in disease and health

orthopedists

Orthopedists

Study the bones, joints, ligaments, tendons, and muscles

endocrinologists

endocrinologists

Study hormone imbalances

rheumatologists

Rheumatologists

Study pain and disorders of the joints, muscles, tendons, bones, and other connective tissues

HPP PATIENT SUPPORT

Enroll in OneSource™ to get personalized patient support from Alexion at 1.888.765.4747.

Learn More about OneSource™
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AT ONESOURCE, WE ARE BY YOUR SIDE THROUGHOUT YOUR JOURNEY, FROM LEARNING ABOUT YOUR CONDITION TO HELPING YOU ACCESS THE THERAPY YOU'VE BEEN PRESCRIBED. PATIENTS' NEEDS ARE OUR TOP PRIORITY.

–Deana,
ONESOURCE CASE MANAGER

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LOOKING FOR HPP RESOURCES?

Understanding HPP is easier when a community of support is eager to help. Explore the
resources available to people living with HPP and their loved ones, including educational events
and connecting with patient advocacy organizations.

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IMPORTANT SAFETY INFORMATION & INDICATION FOR STRENSIQ® (asfotase alfa)

STRENSIQ may cause serious side effects, including

  • Serious allergic (hypersensitivity) reactions happened in some people who use STRENSIQ. Stop using STRENSIQ and go to the nearest hospital emergency room right away if you or your loved one have any of the signs and symptoms of a serious allergic reaction, including
    • Difficulty breathing
    • Swelling of your eyes, lips, or tongue
    • Hives
    • Feeling faint
    • Nausea or vomiting
    • Dizziness
    • Itching of your lips, tongue, or throat
    • Choking sensation
  • Skin thickening or pits at the injection site (lipodystrophy) has happened several months after using STRENSIQ.
  • Calcium buildup in the eyes and kidneys can occur if you or your loved one have HPP. Your healthcare provider should check the eyes and kidneys while you or your loved one use STRENSIQ.
  • Decreased efficacy. Contact your healthcare provider if you or your loved one notice STRENSIQ is no longer working or experience worsening symptoms of HPP (e.g., increased respiratory support, increased difficulty walking, new fractures).

The most common side effects of STRENSIQ include local skin injection-site reactions (red skin patches, bruising, color change, pain, itching, thinning, swelling, pits, and bumps) and calcium buildup in your eyes and kidneys.

STRENSIQ may affect other lab test results, therefore it is important that you present your Medical Alert Card to your healthcare team so they are aware that you are being treated with an alkaline phosphatase (ALP) replacement therapy which may cause incorrect results on certain laboratory tests.

Tell your doctor if you are pregnant or plan to become pregnant or are breastfeeding or plan to breastfeed.

These are not all the possible side effects of STRENSIQ. For more information, ask your healthcare provider or pharmacist. Call your healthcare provider for medical advice about side effects. You may report side effects to the US Food and Drug Administration at 1‑800‑FDA‑1088.

INDICATION
What is STRENSIQ?
STRENSIQ is a prescription medicine used to treat people with perinatal/infantile- and juvenile-onset hypophosphatasia (HPP).

Please see STRENSIQ full Prescribing Information, including Patient Information and Instructions for Use.
IMPORTANT SAFETY INFORMATION & INDICATION FOR STRENSIQ® (asfotase alfa)

STRENSIQ may cause serious side effects, including

  • Serious allergic (hypersensitivity) reactions happened in some people who use STRENSIQ. Stop using STRENSIQ and go to the nearest hospital emergency room right away if you or your loved one have any of the signs and symptoms of a serious allergic reaction, including
    • Difficulty breathing
    • Swelling of your eyes, lips, or tongue
    • Hives
    • Feeling faint
    • Nausea or vomiting
    • Dizziness
    • Itching of your lips, tongue, or throat
    • Choking sensation
  • Skin thickening or pits at the injection site (lipodystrophy) has happened several months after using STRENSIQ.
  • Calcium buildup in the eyes and kidneys can occur if you or your loved one have HPP. Your healthcare provider should check the eyes and kidneys while you or your loved one use STRENSIQ.
  • Decreased efficacy. Contact your healthcare provider if you or your loved one notice STRENSIQ is no longer working or experience worsening symptoms of HPP (e.g., increased respiratory support, increased difficulty walking, new fractures).

The most common side effects of STRENSIQ include local skin injection-site reactions (red skin patches, bruising, color change, pain, itching, thinning, swelling, pits, and bumps) and calcium buildup in your eyes and kidneys.

STRENSIQ may affect other lab test results, therefore it is important that you present your Medical Alert Card to your healthcare team so they are aware that you are being treated with an alkaline phosphatase (ALP) replacement therapy which may cause incorrect results on certain laboratory tests.

Tell your doctor if you are pregnant or plan to become pregnant or are breastfeeding or plan to breastfeed.

These are not all the possible side effects of STRENSIQ. For more information, ask your healthcare provider or pharmacist. Call your healthcare provider for medical advice about side effects. You may report side effects to the US Food and Drug Administration at 1‑800‑FDA‑1088.

INDICATION
What is STRENSIQ?
STRENSIQ is a prescription medicine used to treat people with perinatal/infantile- and juvenile-onset hypophosphatasia (HPP).

Please see STRENSIQ full Prescribing Information, including Patient Information and Instructions for Use.