Isolated growth hormone deficiency type III

Isolated growth hormone deficiency type III (IGHD III) is a rare genetic disorder characterized by insufficient production of growth hormone (GH) from the anterior pituitary gland, leading to impaired linear growth and short stature. Unlike other forms of isolated growth hormone deficiency, IGHD III follows an X-linked inheritance pattern and is caused by mutations in the BTK gene region or associated genes on the X chromosome. Some cases have been associated with agammaglobulinemia, linking this condition to both the endocrine and immune systems. Affected individuals typically present in childhood with proportionate short stature, delayed bone age, and reduced growth velocity compared to age-matched peers. Facial features may appear younger than chronological age, and there can be delayed puberty. In cases associated with immune deficiency, patients may also experience recurrent infections due to impaired antibody production (hypogammaglobulinemia or agammaglobulinemia). The primary treatment for IGHD III is recombinant human growth hormone (rhGH) replacement therapy, which is administered via daily subcutaneous injections during childhood and adolescence to promote linear growth and normalize adult height. Early diagnosis and initiation of treatment are important for optimizing growth outcomes. If associated immunodeficiency is present, immunoglobulin replacement therapy may also be required. Regular monitoring by an endocrinologist is essential to adjust dosing and assess treatment response, including tracking growth velocity, IGF-1 levels, and bone age progression.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

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