Congenital Adrenal Hyperplasia(Pathophysiology)
Ji Keon LOOI

Congenital Adrenal Hyperplasia
• an autosomal recessive diseases (mutation arises on chromosome six)
• lack of an enzyme needed by the adrenal gland to make the hormones cortisol and aldosterone
• pervert or impair development of primary or secondary sex characteristics in affected infants, children, and adults.
• 21-Hydroxylase enzyme deficiency, accounts for approximately 90-95% of all CAH disorders

Result of a 21-Hydroxylase Deficiency
• Accumulation of progesterone and 17-hydroxyprogesterone as a result of a 21-hydroxylase deficiency.

CAH results in 3 disturbances:
• Lack of Cortisol
• Lack of Aldosterone
• Too much Androgen

In Normal Babies
• When babies begin their development within the womb, it is impossible to distinguish male and female genitalia - the "undifferentiated" genitalia of males and females look alike.
• In boys, between approximately 12 to 15 weeks after conception, their testes start producing androgen, which drives the "undifferentiated" genitalia to develop the male structure and characteristics.
• As androgen is not normally produced in the female fetus, this "masculinization" does not occur.

In CAH Babies (female)
• In CAH, however, the adrenal glands of the female overproduce androgen – forcing the girl's genitalia to begin development in the male direction.
• The clitoris is enlarged with the urethral opening at the base and may resemble a small penis.
• In addition, the cleft between the labia or lips may be partly closed over, hiding the entrance to the vagina.
• Often only one opening can be seen, with the urinary passage and vagina both opening into this one entrance.
• Normal internal organs - the vagina, uterus (womb), fallopian tube and ovaries.

Males??
• No obvious problems in newborn males
• changes can be seen long before puberty normally occurs.
• The child becomes increasingly muscular, the penis enlarges, pubic hair appears, and the voice deepens.
• Boys may appear to enter puberty as early as 2-3 years of age.
• At puberty, the testes are small

21-hydroxylase enzyme deficiency
• In more severe forms - adrenal crisis in the newborn due to salt wasting (21-hydroxylase enzyme deficiency).
• severe symptoms shortly after birth- vomiting, dehydration , electrolyte changes, and cardiac arrhythmias .
• Untreated, lead to death within 1 to 6 weeks after birth.

Sources
• http://www.emedicine.com/ped/topic48.htm
• http://www.cah.org.au/index.php?option=com_content&task=view&id=12&Itemid=31
• http://www.umm.edu/ency/article/000411.htm
• http://www.aafp.org/afp/990301ap/1190.html
• http://en.wikipedia.org/wiki/Congenital_adrenal_hyperplasia