hypoinsulinemic hypoglycemia with hemihypertrophy

Hypoinsulinemic Hypoglycemia with Hemihypertrophy (HIHGHH) Description

Hypoinsulinemic hypoglycemia with hemihypertrophy is a rare, genetic, endocrine disease characterized by:

• Neonatal Macrosomia: Newborns are often larger than average.
• Asymmetrical Overgrowth: One side of the body grows more than the other, typically manifesting as left-sided hemihypertrophy.
• Recurrent Severe Hypoinsulinemic Hypoglycemia: Infants experience episodes of reduced consciousness and seizures due to severe low blood sugar levels.

This condition is often associated with:

• Hemihypertrophy: Asymmetrical growth of one side of the body, which can affect various parts such as the face, arm, trunk, and leg.
• Macrosomia: Newborns are larger than average, which can be a sign of this condition.

Key Features

• Rare genetic endocrine disease
• Characterized by neonatal macrosomia and asymmetrical overgrowth
• Recurrent severe hypoinsulinemic hypoglycemia in infancy
• Episodes of reduced consciousness and seizures due to low blood sugar levels

References

• [1] Hypoinsulinemic hypoglycemia and body hemihypertrophy is a rare, genetic, endocrine disease characterized by neonatal macrosomia, asymmetrical overgrowth (typically manifesting as left-sided hemihypertrophy) and recurrent, severe hypoinsulinemic (or hypoketotic hypo-fatty-acidemic) hypoglycemia in infancy, which results in episodes of reduced consciousness and seizures. [1]
• Hypoinsulinemic hypoglycemia with hemihypertrophy is characterized by hemihypertrophy without any other features of Beckwith-Wiedemann syndrome ... [5]
• ORPHA:293964 Hypoinsulinemic hypoglycemia and body hemihypertrophy. The phenotypic description of this disease is based on an analysis of the biomedical ... [6]

Hypoinsulinemic hypoglycemia with hemihypertrophy, a rare genetic endocrine disease, presents with distinct signs and symptoms. These include:

• Neonatal macrosomia: Infants born with this condition often exhibit macrosomia (excessive birth weight) [1].
• Asymmetrical overgrowth: Hemihypertrophy, typically manifesting as left-sided hemihypertrophy, is a characteristic feature of this disease [2][3].
• Recurrent severe hypoinsulinemic hypoglycemia: Infants experience episodes of reduced consciousness and seizures due to recurrent, severe hypoinsulinemic (or hypoketotic hypo-fatty-acidemic) hypoglycemia in infancy [1][4].
• Reduced consciousness and seizures: Episodes of reduced consciousness and seizures are a direct result of the severe hypoinsulinemic hypoglycemia [1][11].

In addition to these specific symptoms, individuals with hypoinsulinemic hypoglycemia with hemihypertrophy may also experience general signs and symptoms associated with low blood glucose levels, such as:

• Thumping heart: A rapid heartbeat can occur due to the release of adrenaline (epinephrine) [12].
• Sweating: Excessive sweating is another symptom caused by the "fight-or-flight" response triggered by epinephrine [12].
• Tingling: Numbness or tingling sensations can also be experienced as a result of low blood glucose levels [12].

It's essential to note that repeated episodes of hypoglycemia can lead to hypoglycemia unawareness, where the body and brain no longer produce warning signs and symptoms, increasing the risk of severe, life-threatening hypoglycemia [14].

Diagnostic Tests for Hypoinsulinemic Hypoglycemia with Hemihypertrophy

Hypoinsulinemic hypoglycemia with hemihypertrophy (HH) is a rare genetic disorder characterized by recurrent episodes of low blood glucose and asymmetrical overgrowth. Diagnosing HH can be challenging, but several diagnostic tests can aid in the diagnosis.

• Glucose Tolerance Tests: These tests measure the body's ability to regulate blood sugar levels after consuming a sugary drink. In individuals with HH, these tests may show abnormal glucose metabolism.
• Glucagon Stimulation Test: This test involves administering glucagon, a hormone that raises blood sugar levels, and measuring the response. A positive glycaemic response (glucose increment of >1.5 mmol/L) to glucagon at the time of hypoglycemia is compatible with HH.
• Octreotide Stimulation Test: Octreotide is a medication that can help regulate blood sugar levels. Administering octreotide and measuring the response can aid in diagnosing HH.
• Genetic Testing: Genetic testing, such as sequence analysis of the AKT2 gene, can confirm the diagnosis of HH. The AKT2 gene is associated with autosomal dominant hypoinsulinemic hypoglycemia with hemihypertrophy (HIHGHH) [9].
• Imaging Studies: Imaging studies, such as ultrasound or MRI, may be used to assess asymmetrical overgrowth and other physical characteristics associated with HH.

Specialist Referrals

Diagnosing HH often requires a multidisciplinary approach involving specialists from various fields. Diagnostic teams for HH may include:

• Endocrinologists
• Geneticists
• Pediatricians
• Radiologists

These specialists can work together to provide an accurate diagnosis and develop a treatment plan tailored to the individual's needs.

References: [10] National Center for Advancing Translational Sciences; ... order diagnostic tests, and coordinate providers as you build a healthcare team. [9] MedGen UID: 343429.

Hypoinsulinemic hypoglycemia with hemihypertrophy (HIHGHH) is a rare genetic disorder characterized by recurrent severe hypoglycemia and asymmetrical overgrowth. The treatment for HIHGHH typically involves a combination of medical management, dietary adjustments, and in some cases, surgical interventions.

Medical Management:

1. Glucose supplementation: Immediate administration of glucose to correct hypoglycemia.
2. Insulin suppression: Medications like diazoxide or octreotide can be used to suppress insulin secretion and prevent further episodes of hypoglycemia.
3. Hormone replacement therapy (HRT): Some patients may require HRT to manage growth hormone excess.

Dietary Adjustments:

1. High-calorie diet: A high-calorie diet is often recommended to help manage the excessive energy expenditure associated with hemihypertrophy.
2. Frequent meals: Eating frequent, small meals throughout the day can help maintain stable blood glucose levels.

Surgical Interventions:

1. Hemihypertrophy surgery: In

Differential Diagnosis of Hypoinsulinemic Hypoglycemia with Hemihypertrophy

Hypoinsulinemic hypoglycemia with hemihypertrophy (HIHGHH) is a rare genetic disorder characterized by neonatal macrosomia, asymmetrical overgrowth, and recurrent severe hypoinsulinemic hypoglycemia in infancy. When considering the differential diagnosis of HIHGHH, several conditions should be taken into account.

• Congenital Hyperinsulinism (CHI): Also known as hyperinsulinemic hypoglycemia, CHI is a heterogeneous condition and represents the most common cause of persistent hypoglycemia in infancy. It is characterized by excessive insulin secretion, leading to severe hypoglycemia.
• Hypoketotic Hypoglycaemia: This condition is associated with suppressed plasma fatty acids and detectable insulin, suggesting congenital hyperinsulinism (CHI).
• Pancreatic Islet Cell Tumor (Insulinoma): Although rare in children, pancreatic islet cell tumors can cause hypoinsulinemic hypoglycemia. A case report describes an elderly man with a pancreatic islet cell tumor presenting with hypoinsulinemic hypoglycemia.
• Mental Retardation, Overgrowth, Facial Dysmorphism, and Hypoglycemia (MORFAN): This rare condition presents with distinctive facies, mental retardation, overgrowth, and recurrent severe hypoinsulinemic hypoglycemia in infancy.

Key Diagnostic Features

When differentiating HIHGHH from other conditions, the following key features should be considered:

• Neonatal Macrosomia: HIHGHH is characterized by neonatal macrosomia, which is not typically seen in CHI or insulinoma.
• Asymmetrical Overgrowth: The presence of asymmetrical overgrowth, particularly left-sided hemihypertrophy, is a distinctive feature of HIHGHH.
• Recurrent Severe Hypoinsulinemic Hypoglycemia: HIHGHH is characterized by recurrent severe hypoinsulinemic hypoglycemia in infancy, which is not typically seen in CHI or insulinoma.

Diagnostic Tests

Certain stimulation tests can aid in the diagnosis of HIHGHH. A positive glycaemic response to i.m./i.v. glucagon at the time of hypoglycaemia is compatible with HH. Additionally, a positive glycaemic response will also be found after subcutaneous octreotide administration.

Conclusion

In conclusion, differential diagnosis of hypoinsulinemic hypoglycemia with hemihypertrophy requires consideration of several conditions, including congenital hyperinsulinism, hypoketotic hypoglycaemia, pancreatic islet cell tumor (insulinoma), and mental retardation, overgrowth, facial dysmorphism, and hypoglycemia (MORFAN). Key diagnostic features include neonatal macrosomia, asymmetrical overgrowth, and recurrent severe hypoinsulinemic hypoglycemia. Certain stimulation tests can aid in the diagnosis of HIHGHH.