isolated growth hormone deficiency type III

Isolated Growth Hormone Deficiency Type III: A Rare Condition

Isolated growth hormone deficiency type III, also known as IGHD3, is a rare genetic disorder caused by mutations in the BTK gene (300300) on Xq22. This condition is characterized by:

• Agammaglobulinemia: Markedly reduced numbers of B cells, which are a type of white blood cell responsible for producing antibodies.
• Short stature: Affected individuals have short stature, delayed bone age, and growth failure.
• Good response to synthetic growth hormone (GH) treatment: People with IGHD3 typically respond well to treatment with synthetic GH.

Key Features

• Inherited in an X-linked recessive pattern, meaning the condition is more likely to affect males than females.
• Associated with agammaglobulinemia and short stature.
• Good response to synthetic growth hormone (GH) treatment.

References

• [1] Description of isolated growth hormone deficiency type III as a condition caused by mutations in the BTK gene.
• [3] IGHD3 is characterized by agammaglobulinemia, short stature, delayed bone age, and good response to synthetic GH treatment.
• [6] Similarities with type II IGHD in terms of very low levels of growth hormone and short stature.
• [10] Caused by genetic mutations, also known as pathogenic variants.

Isolated growth hormone deficiency type III (IGHD3) is characterized by a combination of symptoms, including:

• Short stature: People with IGHD3 typically experience noticeably short stature, which can vary in severity.
• Delayed bone age: The bones do not develop at the normal rate, leading to delayed bone age.
• Agammaglobulinemia: A condition where there is a marked reduction in the number of B cells, which are an essential part of the immune system.

These symptoms are often accompanied by other health issues, such as:

• Fatigue
• Anxiety and depression
• Decreased sexual function and interest
• Feelings of being isolated

It's worth noting that IGHD3 is caused by mutations in the BTK gene and follows an X-linked pattern of inheritance. This means that the condition is more likely to affect males, who have only one X chromosome.

References:

• [8] describes IGHD3 as characterized by agammaglobulinemia and markedly reduced numbers of B cells, short stature, delayed bone age, and good response to treatment with growth hormone.
• [11] states that IGHD3 is characterized by agammaglobulinemia and markedly reduced numbers of B cells, short stature, and delayed bone age.

Diagnostic Tests for Isolated Growth Hormone Deficiency Type III

Isolated growth hormone deficiency type III (IGHD3) can be diagnosed using a combination of clinical findings, imaging studies, and laboratory testing.

• Provocative tests of GH production: These tests are used to assess the body's ability to produce growth hormone. Examples include the insulin tolerance test (ITT), the glucagon stimulation test, and the arginine stimulation test [5].
• Measurement of IGF-I and IGFBP-3: Measuring levels of insulin-like growth factor 1 (IGF-I) and its binding protein 3 (IGFBP-3) can help diagnose GHD. These tests are particularly useful in children with severe GHD [7].
• Macimorelin stimulation test: This is a non-invasive test that involves taking blood samples over several hours to check levels of growth hormone [8].
• GH stimulation testing: This type of testing is commonly used in the diagnostic workup of GHD, except for some clinical conditions that do not require GH stimulation tests for diagnosis [9].

Imaging Studies

In addition to laboratory testing, imaging studies such as pituitary MRI may be used to rule out other conditions that can cause growth hormone deficiency.

Clinical Findings

The diagnosis of IGHD3 is also based on clinical findings, including short stature, delayed bone age, and agammaglobulinemia [1].

It's worth noting that the diagnosis of GHD is a multi-step procedure that involves a combination of these tests and clinical findings. A healthcare provider will use this information to determine the best course of action for diagnosis and treatment.

References:

[1] Context result 1 [5] Context result 5 [7] Context result 7 [8] Context result 8 [9] Context result 9

Treatment Options for Isolated Growth Hormone Deficiency Type III

Isolated growth hormone deficiency type III (IGHD3) is a rare genetic disorder characterized by growth hormone deficiency, short stature, delayed bone age, agammaglobulinemia with markedly reduced numbers of B cells, and a good response to treatment with growth hormone.

Treatment Guidelines

According to the Drug and Therapeutics, and Ethics Committees of the Pediatric Endocrine Society, the clinical management of children and adolescents with growth failure from GHD, ISS, or PIGFD using the best available evidence recommends the use of growth hormone as a treatment option for IGHD3 [13].

• Growth hormone therapy has been shown to be effective in treating IGHD3, with a good response to treatment reported by Conley et al. (1991) [12].
• The treatment typically involves administering recombinant human growth hormone (rhGH) via subcutaneous injections.
• The dosage and duration of treatment may vary depending on the individual patient's needs and response to therapy.

Key Points

• Growth hormone deficiency is a severe shortage or absence of growth hormone, which can lead to short stature and delayed bone age in individuals with IGHD3 [15].
• Agammaglobulinemia, characterized by markedly reduced numbers of B cells, is also a feature of IGHD3.
• Treatment with growth hormone has been shown to be effective in improving growth outcomes and overall health in individuals with IGHD3.

References

[12] Conley et al. (1991) - A study on the use of growth hormone therapy for IGHD3, which reported a good response to treatment.

[13] The Drug and Therapeutics, and Ethics Committees of the Pediatric Endocrine Society's guideline on the clinical management of children and adolescents with growth failure from GHD, ISS, or PIGFD.

[15] A description of isolated growth hormone deficiency as a condition caused by a severe shortage or absence of growth hormone.

**Differential Diagnosis of Isolated Growth Hormone Deficiency Type III