Hypothalamic hamartomas (HH) are rare, tumor-like malformations that occur during fetal development and are present at birth. The lesions usually do not change in size or spread to other locations. Both the type and severity of symptoms vary greatly among patients with Hypothalamic hamartomas. Common symptoms include frequent gelastic seizures (spontaneous laughing, giggling and/or smirking) or dacrystic seizures (crying or grunting); developmental delays; and/or precocious puberty. Additional symptoms may include cognitive impairment; emotional and behavioral difficulties; and endocrine disturbances. These symptoms often start early in life but are frequently misdiagnosed. For some patients, endocrine (hormonal) disturbances such as central precocious puberty may be the only symptom. Though Hypothalamic hamartomas can occur in patients with certain genetic disorders (such as Pallister-Hall syndrome), the majority of cases are sporadic.