Congenital Adrenal Hyperplasia: Causes, Types, Features, Diagnosis, Treatment, Prevention
Congenital adrenal hyperplasia (CAH) is a genetic disorder, in which the adrenal glands are affected. Normally, a person has a pair of adrenal glands, placed over each kidney, which are responsible for producing certain important hormones like cortisol, aldosterone and testosterone. In this condition, the adrenal glands and their hormone production is affected leading to health problems.
The term hyperplasia means overgrowth and in this condition the adrenal glands are overgrown due to the defect, which affects their functioning. Thus, it is characterized by swelling of the adrenal glands and an imbalance of the related hormones.
Causes Of Congenital Adrenal Hyperplasia
Congenital adrenal hyperplasia (CAH) is an inherited disorder caused due to genetic mutations resulting in deficiency of an enzyme, called 21-hydroxylase, related to production of adrenal gland hormones.
Normally, adrenal gland produces building blocks which prepare cortisol with the help of this enzyme. When there is sufficient cortisol in the blood, stimulation of adrenal gland to produce the building blocks stops and the body functions regularly.
In Congenital adrenal hyperplasia (CAH), there is a disturbance in the process of preparation of cortisol from the building blocks due to the lack of this enzyme. As a result the levels of cortisol never rise to the optimum and the stimulation of adrenal gland continues. This causes the adrenal gland to overwork and leads to overgrowth or swelling. Also, the building blocks are released in large amounts, which are not properly utilized and hence they build up in the glands.
One such building block is the male hormone, testosterone, which is produced in excess and is released in the blood; hence elevated blood testosterone levels are seen. As cortisol is not prepared sufficiently, another hormone called aldosterone is also produced less causing adverse effects on the salt levels in the blood.
Types Of Congenital Adrenal Hyperplasia
There are two main types of congenital adrenal hyperplasia
- Classic Congenital Adrenal Hyperplasia– A severe form, usually noted in early childhood
- Non-Classic Congenital Adrenal Hyperplasia– A milder form, usually noted by early adulthood
Clinical Features Of Congenital Adrenal Hyperplasia
The clinical picture depends on the type of Congenital adrenal hyperplasia (CAH) and varies depending on the age.
Clinical Features of Classic Congenital Adrenal Hyperplasia (CAH):
- Poor feeding, vomiting, poor weight gain
- Dehydration, electrolyte imbalance
- Girl babies with ambiguous or abnormal genitalia
- Boy babies may appear normal or have an enlarged penis
In Children And Adults
- Very early signs of puberty
- Irregular menstruation in women
- Infertility in both men and women
- Short stature as an adult
Clinical Features of Non-Classic Congenital Adrenal Hyperplasia (CAH):
As the condition is often noted later, clinical features related to sexual characters become more noticeable. However, some cases may not show any symptom at all.
Young boys and men may have enlarged penis.
In Young Girls And Women
- Irregular or absent menstruation
- Polycystic ovarian disease (PCOD)
- Masculine features like a deep hoarse voice, excessive hair over the body, facial hair
Both Men And Women May Have:
- Early signs of puberty like pubic hair
- Low bone density
- Increased growth and skeletal development during growth phase but short stature as an adult
Persons having congenital adrenal hyperplasia can suffer from salt losing crisis resulting in electrolyte imbalance or can also be at increased risk of hypertension.
Diagnosis of Congenital Adrenal Hyperplasia (CAH):
Severe forms of this condition may be noticeable during infancy due to ambiguous genitalia; however, milder forms may be diagnosed later or during examination for other conditions. A thorough clinical examination by a physician may reveal typical physical characteristics and clinical features.
In Order To Confirm The Diagnosis, Investigations Ordered May Include:
- Blood Tests – To detect the levels of chemical and electrolytes, levels of hormones, aldosterone, cortisol, testosterone.
- X-rays of Bones – To detect skeletal development and bone age
- Pelvis Ultrasound Scan In Girls With Abnormal Genitalia – To study the appearance of kidneys, uterus and genitalia
- Corticotrophin Stimulation Test – To study the way adrenal gland responds to hormone stimulation
- Karyotype Testing – To detect the chromosomal sex in children with abnormal genitalia
- Genetic Testing – To confirm the defect.
Treatment of Congenital Adrenal Hyperplasia (CAH):
Treatment mainly aims at managing the hormone levels as far as possible to prevent or reduce following consequences.
- Medications– Medical treatment involves hormone replacement, which can boost the deficient hormone levels and aid in effective functioning. Glucocorticoids, mineralocorticoids are steroid medications used for this purpose depending on the deficiency of the particular hormone. Some additional medications or dose adjustment may be required during times of infection, surgery or other illnesses.
- Surgery– Reconstructive surgery to correct abnormal genitalia may be considered in some cases. Surgical removal of adrenal glands to minimize hormone effects may be considered depending on the case.
Prevention of Congenital Adrenal Hyperplasia (CAH):
Genetic counseling can help in families with known cases. Prenatal screening and diagnosis can help in detecting the condition before birth. Treatment options of hormone replacement, while the fetus is in the womb are also available. Newborn screening test is available and can also help in early detection and intervention.
For patients under treatment, it is important to:
- Consider using a medical alert accessory or carry an identification card with medical details.
- Consult physician during stressful periods like illness, infection, injury or surgery, as regular monitoring and dose adjustments may be required.
- Plan appropriate diet and carbohydrate intake during exercise, illness, fasting as they can cause sudden drop in blood sugar levels.
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