What is the CLARIFY study?

The CLARIFY study is a disease monitoring study designed to collect information about autosomal dominant hypocalcemia type 1 (ADH1) and type 2 (ADH2) which are conditions that can result in low blood calcium levels. Information collecting studies are essential for understanding the impact and natural history of a particular condition which include its progression and potential complications. These studies are especially valuable in rare conditions since there is not much information available in the medical literature.

ADH1 & ADH2 are inherited conditions, which means parents pass down the condition to their child. Autosomal dominant tells us that each child of an affected parent has a 50% chance of developing the condition. If you have been told that you or your child have low blood calcium levels or hypoparathyroidism not due to surgery, you may be eligible to participate.

Who can join the CLARIFY study?

The CLARIFY study is for people from birth to 90 years of age who have ADH1 or ADH2. If you do not know whether you or your child have ADH1 or ADH2, ask your doctor about a genetic test that can help to provide this information.

What will happen during the CLARIFY study?

Participation in the CLARIFY study lasts about five years. Study participants can expect the following:

Informed Consent

The participant (or a parent or legal guardian if they are younger than 18 years old) is required to read and sign the Informed Consent Form (ICF) before the participant has any tests or procedures.


Participants will complete genetic testing (unless they have previous documentation confirming either a CASR or GNA11 variant for ADH1 or ADH2, respectively) and answer questions about their medical history to confirm if they qualify for the study.

Information Collection

Participants will attend study visits every 6 months for the first 3 years of the study and receive study health tests and procedures that are in line with information collected at follow-up visits for your ADH1/ADH2.

Additional Study Visits

Participants will have study visits once a year for the last 2 years of the study. When this part of the study ends, your participation is complete.

Participation in a clinical study is voluntary. You can ask any questions you have and may leave the study at any time, for any reason.

Is there a study medication? 

No, the goal of the CLARIFY study is to collect information about ADH1 and ADH2 over a long period of time to help doctors and scientists better understand these conditions. You will continue the regimen for ADH1 and ADH2 as prescribed by your physician throughout this study, but no additional medications will be provided as part of the CLARIFY study.

The information gathered from this study can help to drive research, education, and potential development of future treatment. The goal of the CLARIFY study is not to test a new medication.