Non-invasive prenatal diagnosis

Experts' Opinion on the Prenatal Therapy of Congenital Adrenal Hyperplasia (CAH) Due to 21-Hydroxylase Deficiency - Guideline of DGKED in cooperation with DGGG (S1-Level, AWMF Registry No. 174/013, July 2015)

Purpose: This guideline of the German Society of Pediatric Endocrinology and Diabetology (DGKED) is designed to be experts' opinion on the current concept of prenatal therapy for congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH). Several scientific medical societies have also participated in the guideline. It aims to offer guidance to physicians when they counsel affected families about prenatal therapy. Methods: The experts commissioned by the medical societies developed a consensus in an informal process. The consensus was subsequently confirmed by the steering committees of the respective medical societies. Recommendations: Prenatal CAH therapy is an experimental therapy. We recommend designing and using standardized protocols for the prenatal diagnosis, therapy and long-term follow-up of women and children treated prenatally with dexamethasone. If long-term follow-up is not possible, then prenatal therapy should not be performed.

Congenital adrenal hyperplasia in pregnancy: approach depends on who is the 'patient'

Congenital adrenal hyperplasia (CAH) is a group of autosomal-recessive disorders caused by a reduced or absent enzymatic activity at one of the stages of adrenal steroid biosynthesis. Prenatal exposure to androgens leads to external genital masculinization of the affected female child. In pregnancy, the provider may be optimizing care for the woman with CAH or targeting treatment to reduce virilization in the affected unborn child. For the affected adult woman the goals of therapy in pregnancy are to prevent adrenal insufficiency, reduce fetal exposure to androgens and glucocorticoids and to avoid damage to reconstructed genitalia. For prenatal therapy for prevention of virilization of possibly affected female children, dexamethasone is used. However, questions remain about the efficacy and safety of exposing 7/8 unaffected children in the first trimester. Prenatal treatment should only be undertaken after careful discussion with the parents of the risks and benefits in an experienced centre or as part of a research protocol.

Molecular diagnosis of two families with classic congenital adrenal hyperplasia

We investigated the genetic defects in two families with classic congenital adrenal hyperplasia (CAH). Clinical data and vein blood of the family members were collected, hormonal evaluation, karyotype analysis, ultrasound and CT scans were performed, and a direct-sequencing of PCR products of the candidate genes was used to identify the mutations. In family A, Patients A-II:1 and A-II:2 were found to be in a compound heterozygous state for mutations of p.I172N (g.1004T>A) in exon 4 and IVS2-13A/C>G (g.659A/C>G) in intron 2 in CYP21A2 gene, their father A-I:1 and mother A-I:2 were found to carry a heterozygous mutation of IVS2-13A/C>G (g.659A/C>G) and p.I172N (g.1004T>A) respectively. In family B, Patient B-II:1 was detected to carry only one heterozygous mutation of p.I172N; no other mutations in CYP11B1, CYP17A1 or HSD3B2 genes were detected. Her father B-I:1 carried a heterozygous mutation of p.I172N (g.1004T>A) and her mother B-I:2 was found to be a wild type in all the candidate genes. Obviously, patients A-II:1 and A-II:2 inherited the p.I172N (g.1004T>A)-bearing maternal allele and the IVS2-13A/C>G (g.659A/C>G)-bearing paternal allele. And this kind of compound heterozygous mutations caused simple virilising (SV) CAH. While patient B-II:1, whose phenotype was SV CAH too, was found to carry only one heterozygous mutation of the p.I172N (g.1004T>A)-bearing paternal allele, and needed further studies.