Heterozygosis for CYP21A2 mutation considered as 21-hydroxylase deficiency in neonatal screening

Arq Bras Endocrinol Metabol. 2008 Nov;52(8):1388-92. doi: 10.1590/s0004-27302008000800030.

Abstract

Steroid 21-hydroxylase deficiency (21-OHD) accounts for more than 90% of congenital adrenal hyperplasia. CAH newborn screening, in general, is based on 17-hydroxyprogesterone dosage (17-OHP), however it is complicated by the fact that healthy preterm infants have high levels of 17-OHP resulting in false positive cases. We report on molecular features of a boy born pre-term (GA = 30 weeks; weight = 1,390 g) with elevated levels of 17-OHP (91.2 nmol/L, normal < 40) upon neonatal screening who was treated as having CAH up to the age of 8 months. He was brought to us for molecular diagnosis. Medication was gradually suspended and serum 17-OHP dosages mantained normal. The p.V281L mutation was found in compound heterozygous status with a group of nucleotide alterations located at the 3' end intron 4 and 5' end exon 5 corresponding to the splice site acceptor region. Molecular studies continued in order to exclude the possibility of a nonclassical 21-OHD form. The group of three nucleotide changes was demonstrated to be a normal variant since they failed to interfere with the normal splicing process upon minigene studies.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 17-alpha-Hydroxyprogesterone / blood
  • Adrenal Hyperplasia, Congenital / blood
  • Adrenal Hyperplasia, Congenital / diagnosis*
  • Adrenal Hyperplasia, Congenital / genetics
  • False Positive Reactions
  • Female
  • Heterozygote
  • Humans
  • Infant, Newborn
  • Male
  • Mutation / genetics*
  • Neonatal Screening*
  • Pregnancy
  • Premature Birth
  • Steroid 21-Hydroxylase / genetics*

Substances

  • 17-alpha-Hydroxyprogesterone
  • CYP21A2 protein, human
  • Steroid 21-Hydroxylase