Discovering X-linked acrogigantism: a new infant-onset overgrowth syndrome
Pituitary gigantism is a very rare condition wherein a tumor on the pituitary gland causes over-secretion of growth hormone, leading to excessive body growth. About half the cases of gigantism are of unknown genetic origin. Therefore, understanding the underlying genetic defects is extremely important for providing correct diagnosis and treatment.
IRP researchers led by Constantine A. Stratakis, M.D., D(med).Sci., discovered a new syndrome of early childhood–onset gigantism that occurs when a small portion of the X chromosome, including the GPR101 gene, is abnormally duplicated. This new condition, which they named X-linked acrogigantism (X-LAG), explains about 10% of all cases of gigantism and as many as 80% of pre-pubertal cases. The team extensively examined the clinical and hormonal symptoms of X-LAG, as well as patients’ responses to therapy. Finally, the investigators characterized the culprit gene, GPR101, at the molecular level.
The discovery and characterization of X-LAG offers pediatricians the appropriate diagnostic tools to recognize the disease early in life, initiate treatment, and provide genetic counseling. Moreover, the findings offer the opportunity to study a new important pathway involved in the central regulation of human growth.
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