Lipoid congenital adrenal hyperplasia
What is Lipoid Congenital Adrenal Hyperplasia?
Lipoid congenital adrenal hyperplasia (LCAH) is an inherited endocrine disorder that the rarest form of congenital adrenal hyperplasia (CAH). It presents in infants shortly after birth (typically a few weeks) and can be fatal if unrecognized and untreated. This is caused by very low or unmeasurable levels of all steroid hormones due to mutations in the StAR gene. The diagnosis of LCAH is generally made using information regarding genetic sex (XY male or XX female), blood hormone levels, and visualization of the adrenal glands (the glands that produce hormones that sit on top of the kidneys).
The type of inheritance associated with LCAH is autosomal recessive, meaning that the parents of a child with LCAH each carry one copy of the StAR gene with a mutation and are unaffected. Both parents passed on their copy of the StAR gene with the mutation to their child with LCAH, who then has two StAR genes that each have a mutation (in other words, no working StAR genes).
The symptoms of LCAH (classic form) typically appear between 2 weeks of life to 3 months of life, prompting medical evaluation. Parents should watch for poor feeding, low blood pressure, and dehydration; infants will also start to have poor weight gain and vomiting. One of the classic signs of the disorder is salt-wasting (loss of sodium that is essential for the body through the urine). Individuals with the non-classic form may not present with symptoms until a few years after birth. Both XY males and XX females have external female genitalia.
The treatment for LCAH is similar to that for CAH. The salt-wasting (losing of salt through urine) should be managed with saline, and the mineralcorticoid deficiency (steroid/hormone deficiency) should be treated by giving fludrocortisone (controls the amount of sodium and fluids in the body). Glucocorticoids are steroid hormones that help the body process carbohydrates, proteins, and fats; these can be provided at minimal replacement doses. The XX females may require estrogen at puberty, and the XY males will need to have their undescended (and non-functional) testes removed due to cancer risk. With appropriate treatment, patients with LCAH can now survive into adulthood.
For more information and support, please visit the Congenital Adrenal Hyperplasia Education and Support Network, a support network for individuals and families affected by CAH, which can be found by visiting http://www.congenitaladrenalhyperplasia.org/.
SOURCE: Emory University - Department of Human Genetics in collaboration with ThinkGenetic • https://www.thinkgenetic.com/diseases/lipoid-congenital-adrenal-hyperplasia/overview/17219 • DATE UPDATED: 2016-06-15
Bose, H. S., Sato, S., Aisenberg, J., Shalev, S. A., Matsuo, N., Miller, W. L. Mutations in the steroidogenic acute regulatory protein (StAR) in six patients with congenital lipoid adrenal hyperplasia. J. Clin. Endocr. Metab. 85: 3636-3639, 2000.