On June 1, 1989, the Texas Department of State Health Services (DSHS) began testing all newborn screening specimens for Congenital Adrenal Hyperplasia (CAH). A defect in the enzyme 21-hydroxylase, which occurs in 95% of CAH cases, is identified by assessing the level of 17-alpha-hydroxyprogesterone. Newborns with this autosomal recessive disorder are often masculinized prenatally. Females may show ambiguous genitalia with labial fusion and clitoral enlargement, sometimes resulting in a male sex assignment. CAH in male newborns is not easily identifiable and may be missed. Some physicians have noted that the scrotum may be slightly darkened, but this is not diagnostic.
In addition to virilization, affected individuals may be "salt-losers". Newborns with salt-losing CAH may become dull, listless and comatose within the first 10-14 days of life. They may exhibit anorexia, vomiting, dehydration, weight loss and apathy. If untreated, death occurs within weeks. Early symptoms may resemble pyloric stenosis. These babies must be identified and treated as soon as possible. Early screening is very important to identify affected babies. The specimen MUST reach the DSHS laboratory as early as possible. "Sick" newborns can be missed if not screened. It is imperative that they be appropriately treated and referred immediately to the nearest pediatric endocrinologist. Treatment involves replacement of the hormones which the baby cannot produce: cortisone and aldosterone.
Children with simple virilizing CAH may be asymptomatic at birth, but due to an excess of androgens (masculinizing hormones), may show abnormal growth and progressive virilization. Boys may show pseudo-precocious puberty (with no testicular enlargement). Girls almost always show masculine characteristics and clitoral enlargement. Although these children may show excessive growth at an early age, premature closure of bone epiphyses results in very short adult stature. It is very important that the simple virilizing type of CAH also be identified and treated early to avoid these problems.
The 17-alpha-hydroxyprogesterone (17-OHP) level is elevated in the child with a 21-hydroxylase deficiency. This can be measured in the dried blood specimen submitted to the DSHS Laboratory on all newborns.
After several years of screening for CAH, cut-off levels have been adjusted and protocols changed to make follow-up less difficult for the primary care provider and yet not "miss" a case. Our data reinforces the importance of the second screen, as several cases of CAH have been normal on the initial screen and abnormal on the second. While these cases may be less severe, it is important to identify them as early as possible.
If the 17-OHP is elevated, Newborn Screening (NBS) personnel at DSHS evaluates the level of 17-OHP, the age of the child, and the birth weight (prematurity), then make appropriate recommendations for follow-up to the physician (or designee) by letter, telephone, or fax. Correct information must be submitted on the form regarding the date of birth, weight and status to assure appropriate follow up of abnormal specimens. Any elevation of 17-OHP should alert the physician to check sodium and potassium levels and examine the genitalia of female infants for ambiguity. Abnormal findings indicate the need for a serum 17-OHP and referral to a pediatric endocrinologist. Even if clinical findings are normal, NBS personnel may urge the physician to do a serum 17-OHP and refer the child to a pediatric endocrinologist if the results of the screening test(s) are very high or if the second screen is abnormal. It is important that babies who show a very high 17-OHP receive a medical evaluation immediately. If a newborn appears to be going into shock and the screening test results have not yet been reported, you may contact DSHS to see if there is more information about the preliminary 17-OHP. A letter will be sent to the neonatologist (or designee) requesting a repeated screening test on these newborns.
A list of pediatric endocrinologists who have worked with the Texas Newborn Screening Program will be sent to the primary care physician when a severely abnormal CAH test is reported. The endocrinologist will work with the primary care physician to assure normal growth and development of the child.