Pseudohypoparathyroidism type 1a (PHP1a) is a rare disease that causes childhood obesity and learning difficulties. This study will investigate eating behaviors and perform cognitive testing on children with PHP1a. The investigators will compare their results to those of healthy siblings and other obese children.

Pseudohypoparathyroidism type 1a (PHP1a) is a genetic disorder that causes early-onset, syndromic obesity and cognitive impairment. This study aims to evaluate eating behaviors, cognition and executive function in children with PHP1a, compared with healthy siblings and matched obese controls.

Inclusion Criteria:

• Clinical diagnosis of PHP1a, sibling of a patient with PHP1a or matched obese control

Exclusion Criteria (PHP1a):

• Treatment with appetite-altering drug or initiation of a new weight loss program in the past 3 months
• Type 2 diabetes

Exclusion Criteria (Controls):

• Obesity due to a genetic syndrome, growth hormone deficiency, untreated hypothyroidism, Cushing syndrome or exogenous glucocorticoid administration
• Weight loss greater than 10% over the previous 6 months
• Autism or other significant learning disorder
• Type 2 diabetes
• Other significant medical condition

Children with pseudohypoparathyroidism type 1a (PHP1a), their healthy siblings and matched obese controls

1 day

Adverse events were recorded during the study visit only.