This study is sponsored by Children's Hospital of Philadelphia Department of Radiology. The purpose of this research is to study 18F-L-Fluoro-DOPA (F-DOPA), a tracer, which is used to take pictures of the pancreas. This imaging test is called an F-DOPA PET scan. The F-DOPA tracer is used to highlight areas of the pancreas that make too much insulin on the PET scan images. The test includes a CT scan (computerized tomography) done at the same time on the same machine, to help define exactly where the highlighted area is located within the pancreas and determine the location of blood vessels and other vital structures. Who can participate:

• Infants, children and adults with hyperinsulinemic hypoglycemia, diagnosed by a fasting test and/or response to glucagon stimulation
• Any age, from birth on
• Requiring surgery to remove part or all of the pancreas

The goal of the study extension is to see whether the incretin hormone GIP increases insulin secretion in individuals with CF and normal glucose tolerance compared to individuals without CF and normal glucose tolerance. This study includes 3 or 4 visits.

The purpose of this research study is to examine and understand the various mechanisms that contribute to CFRD and gain a better understanding of potential means to treat CFRD. Participation will include 2-3 visits, home monitoring, and will last about 2 years.

Our team at the Congenital Hyperinsulinism Center at CHOP is working on a research study to determine whether an experimental gene therapy product, DTX401, is safe and effective in people with glycogen storage disease type Ia (GSDIa). The FDA has not approved this drug for the treatment of GSDIa but has approved us to use this drug as part of this clinical trial. The purpose of this research study is to see if DTX401 can help people with GSDIa have normal blood sugar levels and fewer episodes of hypoglycemia. DTX041 works by delivering copies of the G6PC gene to your liver through a one-time infusion. Participation in this study will last for 2 years and will involve 30 study visits. It is possible that treatment with the study drug infusion may improve your blood sugar levels. Travel costs will be covered by the study and you will receive compensation for participating.

NAD+ (nicotinamide adenine dinucleotide) is an important substance found in the body that plays a role in energy metabolism and overall health. The purpose of this research study is to test the performance of a new magnetic resonance imaging (MRI) technique (spectroscopy) to measure NAD+ metabolism in brain and skeletal muscle. MRI provides pictures of the inside of the body and information about chemicals the body makes.We are seeking to enroll males and females with Friedrichs Ataxia (FA) as well as healthy matched volunteers, 18 years of age and above. Pregnant females excluded for safety purposes.

The purpose of the study is to determine changes in lactate and creatine in calf muscle of healthy adult volunteers. Males and females of different ages (18 - 30 years, 45-55 years, and 70-80 years) will be asked to attend a single in-person study visit. Prior to the completing the MRI scan, the study team will review the health status of individuals.

The purpose of this research study is to learn more about Graves disease and PTC/Hypothyroidism, How it effects brain function and brain function changes after starting medical treatment.

Congenital Hyperinsulinism is the most common cause of low blood sugar (hypoglycemia) in infants and children.Infants who are born with this problem have low blood sugar, which can cause seizures or brain damage.

We are doing this study to see if the patterns of abnormalities in controlling insulin in children and adults with hyperinsulinism are related to any underlying genetic cause and to identify possible new genetic causes.This will be done by standard clinical tests of insulin control: a glucose tolerance test, a protein tolerance test, and a fasting test.

Our team is working on a study to better understand neurological problems, including seizures and developmental delays, that occur in children with hyperinsulinism, including HI/HA syndrome, and type 1 diabetes mellitus. The study involves a one-day visit to The Children's Hospital of Philadelphia and The University of Pennsylvania for a specialized magnetic resonance imaging scan (MRI) of the brain, an electroencephalogram (EEG), blood draw, and completion of questionnaires to evaluate development and behavior. The entire study visit is expected to take about five hours. If you are interested in learning more, please contact us at HIResearch@email.chop.edu.

You or your child are being asked to take part in this research study because you have Glycogen Storage Disease Type III (GSD III). The purpose of this research study is to better understand blood sugar variability, muscle strength and function, and impact of Glycogen Storage Disease Type III (GSD III) on overall health. You will not receive any treatment for your GSD III as part of this study, but the information you provide will be helpful for the study sponsor, Ultragenyx Pharmaceutical Inc., to develop a new therapy for GSD III.

If you agree to take part, your participation will last for about 26 weeks and will involve up to 2 study visits to the hospital along with up to 26 phone calls. There will be no changes to your treatment regimen for GSD III as part of this study.

As a participant in the research you will:

• come to the hospital for 1-2 in person visits to complete interviews and questionnaires,
• wear a blinded continuous glucose monitor (CGM) 3 months and an unblinded CGM for 3 months,
• complete fingerstick blood sugar checks, maintain a nutrition diary for 3 or more weeks throughout the study,
• maintain a hypoglycemia symptom diary, and
• upload CGM and HHG device data to a study-provided laptop weekly.

The main risks of this study are from hypoglycemia related to your diagnosis of GSD III and a loss of confidentiality. There are no direct benefits to you for participating in this study but the information collected as part of this study will help researchers better understand GSD III.