Prevalence of classical forms of 21-hydroxylase deficiency in Western Siberia according to the results of neonatal screening of congenital adrenal hyperplasia
LA Suplotova, EB Hramova, OB Makarova, NU Yuzakova & TV Barcova
The purpose: to study prevalence of classical forms of 21-hydroxylasae deficiency according to the results of neonatal screening on a congenital adrenal hyperplasia (CAH) in Tyumen, Russia.
The analysis of neonatal screening on CAH results in Tyumen for the period of 20032004. For the period under research 20011 newborn have been tested on the 17-OHP level. Measurement of 17-hydroxyprogesterone in blood samples was done in the central laboratory by the ELISA method sing sets Delfia Neonatal 17-OHP. The maximum normal quantity of 21-hydroxylasae is 17-OHP 60 nmol\l.
Results: In the first test among 20 011 newborn Tyumens there were 124 persons with 17-OHP level above 60 nmol/l, that makes 0.61%. According to the results of repeated test for 17-OHP from these 124 persons 2 male children with 21- hydroxylase deficiency have been revealed. Thus, frequency of classical forms of CAH in the Tyumen population is determined as 1: 10 005 newborns. The rest of newborn with 17-OHP level above normal 122 persons (98.3%) had transitional character of 17-OHP level increase.
Sensitivity of the research method is determined as 100%, i.e. children with CAH in 100% had rising 17-OHP level. Specificity has made 99%, efficiency of the used method −99.4%.
In order to study influence of gestational age and body weight of newborn on the level of neonatal 17-OHP, all the tested newborn children have been divided in 2 groups. In the first one the average weight at birth was of 2139±345 g. and in the second one of 3448±504 g. (P=0.000), the average gestation term was of 33±1. 4 week and 38.8±0.9 weeks respectively (P=0.000). The 17-OHP level obviously differed in these 2 groups P=0.015. The correlation analysis also revealed weak negative interrelation between these characteristics r=−0.18, P=0.007. Thus, the research shows the dependence of the level of neonatal 17-OHP on body weight and gestation age of newborn children.