Congenital Adrenal Hyperplasia: Causes, Symptoms and Treatment

Adrenal glands are the small size organ located on the top of the kidney. Congenital adrenal hyperplasia is not a single disease, it is a group of inherited disorders that affects adrenal glands. The adrenal glands produce hormones that are responsible for regulation of metabolism, blood pressure, the immune system and other essential functions of the body.

The affected people lack an enzyme by which the adrenal glands forms hormones like cortisol or mineralocorticoids. This lack of enzyme results in these hormones and often overproduction of sex hormones. The signs and symptoms differ from person to person.

The worldwide date shows that the prevalence is approximately 1 in 15,000 live births.

Symptoms of Congenital Adrenal Hyperplasia

The signs and symptoms depend upon the type of CAH, the age of diagnosis and the gender of the affected individual. There are broadly two types of congenital adrenal hyperplasia, classic and non-classic

Classic form: This is more severe form of the disease and usually come to notice in infancy. The symptoms are either related to salt wasting or simple virilizing

In salt wasting CAH, the adrenals glands make too little aldosterone, low cortisol and high sex hormones. So, the symptoms are of both salt wasting and virilization. Aldosterone helps in retaining sodium in the body. So, low aldosterone causes increased sodium in the body and symptoms are

• Dehydration
• Diarrhea and vomiting
• Abnormal heart rhythms
• Low blood pressure

There are symptoms of increased male sex hormones like

• Abnormal genitals in newly born female child
• Enlarged or normal genitals of male child
• Virilizing symptoms: virilizing is a condition occurring in small boys and females due to excess of male sex hormones like boys and girls before puberty attain rapid growth, adult body hair pattern, deep voice irrespective of gender, early beard in males, well developed muscles, acne.
• In adult females, it causes deepening of voice, irregular menstrual period, falling of hair, acne
• In virilizing form of classic CAH, the symptoms are those of virilization as described above and no salt wasting symptoms are seen

Nonclassic CAH

This is less severe form of the CAH and it is generally not detectable until late childhood or early adulthood. Most symptoms are related to the increase concentrations of male sex hormones and include features of virilization as

• Early signs of puberty
• Severe Acne
• Irregular or abnormal menstrual period in females
• Rapid growth in height in childhood which becomes shorter than expected

Sometimes signs are so mild that they never knew that they have nonclassic CAH.

Causes of Congenital Adrenal Hyperplasia

The CAH is an inherited disease where the genes which codes the enzyme are mutated means thee genes are different from usual. So, the enzyme formed will also be different from the usual that is non- functional. This disease follows the pattern of autosomal recessive where the child must get that mutated gene from both the parents. It means if parents are normal their child can be abnormal only if both the parents carry the mutated gene. The most common enzyme which is deficient in 95% of cases is 21-hydroxylase. The normal functioning of enzymes converts the substrate into hormone. Substrate is the molecule on which enzyme acts. Deficiency of this enzyme causes accumulation of substrate. These substrate in increased concentration is now utilized by different set of enzymes to form the male sex hormones or androgens.

Therefore, the lack of the main hormones and excess androgens is responsible for all the signs and symptoms.

Diagnosis of Congenital Adrenal Hyperplasia

Your doctor will use your medical history, conduct a physical examination and order some tests to establish a diagnosis

Medical history: The doctor will ask the parents complete details about

• The symptoms of child
• Any family history of inherited disorders
• any screening tests done at childhood

Physical examination: Your doctor will examine the body of the child completely especially the genital system. Child with the classic CAH present the signs and symptoms early while the nonclassic is not suspected until adulthood.

Tests: In United states all newborns are screened for a variety of conditions that also includes 21-hydroxylase enzyme deficiency, there is no screening tests to detect nonclassic CAH.

• Screening test: A small sample of blood is taken from the heel of the child and the level of substrate is detected. In classic form of CAH the substrate level is very high.
• Test after infancy: in countries where screening tests are not available then the same test is done after infancy when the parents complain of signs and symptoms.  
• Blood and urine test: it is used to test the level of hormones. Abnormal levels of hormone can be used to make the diagnosis.
• Prenatal testing: If other children of parents are having CAH and there is family history of CAH, then a child can be tested before he or she is born.

Treatment of Congenital Adrenal Hyperplasia

The main goals of the treatment are to reduce the concentration of androgens and maintaining the levels of deficient hormone. Treatment depends upon the type of CAH and the severity of signs and symptoms.

For classic CAH

• Hormone replacement therapy: The patients have to take the steroids daily for their whole life which includes corticosteroids and mineralocorticoids.
• Salt supplementation can also be given if salt wasting is severe.
• Surgery: Girls which are born with abnormal genitals can undergo surgery for proper functioning of these organs.

These people are followed closely as the dose is to be modified at different times according to the condition of the patient

For nonclassic CAH

The signs are so mild that these people don’t require treatment. If some symptoms are there, then small doses of corticosteroids can be given.

Prognosis of Congenital Adrenal Hyperplasia

If the hormone replacement therapy is successfully started, then the symptoms are managed and the child can live a normal adult life.

References:

• Congenital adrenal hyperplasia. Genetic and Rare Diseases Information Centre
• Pediatric endocrinology fact sheet: Congenital adrenal hyperplasia (CAH) ― A guide for families. American Academy of Pediatrics and Pediatric Endocrine Society
• The American Association of Clinical Endocrinologists