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X-linked adrenal hypoplasia congenita is a genetic
that mainly affects males. It involves many endocrine tissues in the
body, especially the adrenal glands.
One of the main characteristics of this disorder is adrenal
insufficiency, a reduction in adrenal gland function that results
from incomplete development of the gland's outer layer (the adrenal
cortex). Adrenal insufficiency typically begins in infancy or in
childhood and can cause vomiting, difficulty with feeding,
dehydration, extremely low blood sugar (hypoglycemia), and shock. However,
adult-onset cases have also been described.
Affected males may also lack male sex hormones, which leads to
underdeveloped reproductive tissues, undescended testicles (cryptorchidism),
delayed puberty, and an inability to father children (infertility). These
characteristics are known as hypogonadotropic hypogonadism. Females are
rarely affected by this disorder, but a few cases have been
reported of adrenal insufficiency or a lack of female sex hormones,
resulting in underdeveloped reproductive tissues, delayed puberty,
and an absence of menstruation.
Mutations in the NR0B1 gene located on the X chromosome (Xp21.3-p21.2) cause X-linked
adrenal hypoplasia congenita. The NR0B1 gene provides
instructions to make a transcription factor protein called DAX1
that helps control the activity of certain genes. When the
NR0B1 gene is deleted or mutated, the activity of certain
genes is not properly controlled. This leads to problems with the
development of the adrenal glands, two structures in the brain (the hypothalamus and pituitary
gland), and reproductive tissues (the ovaries or testes).
These tissues are important for the production of many hormones
that control various functions in the body. When these hormones are
not present in the correct amounts, the signs and symptoms of
adrenal insufficiency and hypogonadotropic hypogonadism can result.
This condition is inherited in an X-linked recessive pattern.
- ^ Domenice S, Latronico AC, Brito VN,
Arnhold IJ, Kok F, Mendonca BB (September 2001). "Adrenocorticotropin-dependent precocious puberty of
testicular origin in a boy with X-linked adrenal hypoplasia
congenita due to a novel mutation in the DAX1 gene". J.
Clin. Endocrinol. Metab. 86 (9): 4068–71. PMID 11549627. http://jcem.endojournals.org/cgi/pmidlookup?view=long&pmid=11549627.
- ^ Tabarin A, Achermann JC, Recan D, Bex V,
Bertagna X, Christin-Maitre S, Ito M, Jameson JL, Bouchard P
(February 2000). "A novel mutation in DAX1
causes delayed-onset adrenal insufficiency and incomplete
hypogonadotropic hypogonadism". J. Clin.
Invest. 105 (3): 321–8. doi:10.1172/JCI7212. PMID 10675358. PMC 377437. http://dx.doi.org/10.1172/JCI7212.
This article incorporates public domain text from The U.S. National Library of Medicine