What is Lipoid Congenital Adrenal Hyperplasia?
Lipoid congenital adrenal hyperplasia (LCAH) is the most severe form of congenital adrenal hyperplasia. The majority of cases are due to mutations in the STAR gene that produces the steroidogenic acute regulatory (StAR) protein.
Individuals with LCAH have a significantly diminished ability to produce almost all adrenal (gland located above the kidneys) and gonadal (testis or ovary) steroid hormones due to improper conversion of cholesterol in the body. The resulting hormone deficiencies cause a classic severe form of the disease, but a milder, non-classic form has also been described.
Severe disease results from mutations that leave little to no enzyme activity of the StAR protein. However, onset of symptoms can be variable. Affected individuals usually experience salt-wasting crises in early infancy, where the body cannot retain salt leading to dehydration and other complications that can be life-threatening. In addition, they may also experience lethargy, poor feeding, and/or darkened (hyperpigmented) skin. Almost all affected individuals also have female genitalia regardless of genetic sex, and some have been described with neurological abnormalities.
Non-classic disease results from mutations that do not completely eliminate activity of the StAR enzyme, however this does not prevent salt-wasting crises. Although there have only been a handful of cases, individuals with non-classic LCAH seem to present in infancy or early childhood. The condition has been described as a form of non-autoimmune Addison disease. The improper adrenal function can result in darkening of skin (hyperpigmentation), low blood sugar (hypoglycemia), vomiting, and other symptoms.
How common is Lipoid Congenital Adrenal Hyperplasia?
LCAH has been reported in many ethnic groups, however the global incidence is unknown. It has been repeatedly seen in the Japanese, Korean, Palestinian, Saudi Arabian, and Swiss populations, possibly due to founder effects (high frequency of disease because the group arose from a small, isolated population) in some of those populations.
How is Lipoid Congenital Adrenal Hyperplasia treated?
Currently, there is no cure for LCAH. However, hormone replacement therapy is indicated for affected individuals and early, consistent adherence to medication may extend the lifespan into adulthood. A multidisciplinary team of physicians, including an endocrinologist, will likely monitor the medication dosage, medication side effects, growth, and development (both general and sexual) of patients who continue to receive treatment.
What is the prognosis for a person with Lipoid Congenital Adrenal Hyperplasia?
In the absence of any interventions or treatment, LCAH is typically fatal in early infancy, although some individuals have survived to adulthood with treatment.