Neonatal screening for congenital adrenal hyperplasia in Southern Brazil: a population based study with 108,409 infants.

BACKGROUND: Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder associated with inborn errors of steroid metabolism. 21-hydroxylase enzyme deficiency occurs in 90 to 95% of all cases of CAH, with accumulation of 17 hydroxyprogesterone (17-OHP). Early diagnosis of CAH based on newborn screening is possible before the development of symptoms and allows proper treatment, correct sex assignment, and reduced mortality rates. This study describes the results obtained in the first year of a public CAH screening program in the state of Rio Grande do Sul, Brazil. METHODS: We reviewed the screening database in search of babies with suspected CAH, that is, altered birth-weight adjusted 17-OHP values at screening. The following data were analyzed for this population: screening 17-OHP values, retest 17-OHP values, serum 17-OHP values for those with confirmed CAH on retest, maternal and newborn data, and family history of CAH. For the screening program, 17-OHP levels are determined on dried blood spots obtained in filter paper with GSP solid phase time-resolved immunofluorescence. RESULTS: Of 108,409 newborns screened, eight were diagnosed with CAH (four males, four females). The incidence of CAH in the state was 1:13,551. Six cases were identified as classic salt-wasting CAH and two were cases of virilizing CAH. The positive predictive value (PPV) of the initial screening (before diagnostic confirmation) was 1.6%. The overall rate of false positive results was 0.47%. The number of false positive results was higher among newborns with birth weight < 2000 g. CONCLUSION: The present results support the need for CAH screening by the public health care system in the state, and show that the strategy adopted is adequate. PPV and false positive results were similar to those reported for other states of Brazil with similar ethnic backgrounds.

Nager syndrome and Pierre Robin sequence.

Nager syndrome is considered a rare genetic syndrome characterized by craniofacial and radial anomalies. Pierre Robin sequence is a triad that includes micrognathia, cleft palate and glossoptosis. The present patient had typical findings of Nager syndrome and Pierre Robin sequence. He progressed to severe respiratory distress, requiring mechanical ventilation and tracheostomy. At 1 year and 11 months, he had episodes of cardiorespiratory arrest and died. In the literature review, we identified the clinical description of 44 patients with Nager syndrome. Among them, 93.1% had micrognathia, 38.6% cleft palate and 11.3% glossoptosis. Only one (2.3%) had all three features, as observed in the present patient. Therefore, despite the fact that the features of Pierre Robin sequence are common, there are few patients who have the complete triad. It is noteworthy, however, that they may be associated with respiratory distress, which may put the patient's life at risk.