Which are the symptoms of Congenital Hyperinsulinism?

Congenital Hyperinsulinism (CHI) is characterized by persistent, unregulated insulin secretion from pancreatic beta cells, leading to recurrent and severe hypoglycemia (low blood sugar). Common symptoms in infants include lethargy, poor feeding, jitteriness, seizures, and apnea, which occur because the brain is deprived of its primary fuel source, glucose.

What are the primary symptoms of Congenital Hyperinsulinism?

The clinical presentation of Congenital Hyperinsulinism is driven entirely by the effects of low blood sugar on the body. Because insulin levels remain high despite low glucose, the body cannot access its energy stores. In newborns, symptoms of Congenital Hyperinsulinism can be subtle, such as irritability or mild tremors, but they can quickly escalate to life-threatening events like generalized seizures or loss of consciousness. It is vital to recognize that symptoms vary significantly; some infants present with severe, sudden-onset hypoglycemia, while others may experience milder, more chronic fluctuations that are harder to detect.

What are the early warning signs to monitor?

Families should remain vigilant for specific indicators that suggest a child is struggling to maintain glucose levels. Early warning signs of Congenital Hyperinsulinism include:

• Feeding difficulties: Weak sucking or refusal to feed.


• Neurological changes: Excessive lethargy, "floppiness," or unusual irritability.


• Autonomic responses: Sweating (diaphoresis), pallor (pale skin), or rapid heart rate.


• Physical tremors: Visible jitteriness or shaking that does not resolve.


• Apnea: Brief pauses in breathing during sleep or feeding.

How does Congenital Hyperinsulinism impact daily life?

Living with Congenital Hyperinsulinism requires constant vigilance, as the risk of neuroglycopenic damage—brain injury caused by prolonged low blood sugar—is a major concern. Patients with Congenital Hyperinsulinism often require frequent feedings, continuous glucose monitoring (CGM), and sometimes specialized medications like diazoxide or octreotide. These demands can create significant stress for families and impact developmental milestones if blood sugar levels are not tightly regulated. As children grow, the severity of Congenital Hyperinsulinism may stabilize in some, while others may continue to require surgical intervention, such as a partial or near-total pancreatectomy.

When should I seek immediate medical attention?

You must seek emergency care if an individual with Congenital Hyperinsulinism exhibits a seizure, loses consciousness, or becomes unresponsive. Any blood glucose reading below 50 mg/dL (2.8 mmol/L) in a suspected case requires immediate clinical evaluation to prevent permanent neurological impairment.

Next steps

• Consult a pediatric endocrinologist experienced in managing hyperinsulinemic states.


• Join the DiseaseMaps.org community to connect with other families navigating this rare condition.


• Request a referral to a center of excellence specializing in pancreatic disorders for genetic testing and surgical consultation.

Medical disclaimer: This content is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Congenital hyperinsulinism.


• Orphanet: Hyperinsulinemic hypoglycemia, familial.


• OMIM (Online Mendelian Inheritance in Man): Hyperinsulinemic hypoglycemia, familial; HHF.


• Congenital Hyperinsulinism International (CHI): Patient resources and clinical guidelines.