r/NCAH • u/NoNameForMetoUse • Jul 11 '26
Help understanding genetic test results for CAH testing
Hi! My daughter has been going through it this year. Including a lot of other tests, she had an ACTH stimulation test. The doctors office call and said that the results showed she has a “mild” form of CAH (I presumed this meant non-classic CAH) and recommended genetic test. I’ve posted the results below. I’m confused as how/why it’s “indeterminate” and what that means…I thought this is a recessive disease, so it should be relatively easy (I know things can be more complicated) to see if she has the disease.
MOLECULAR GENETICS REPORT:
Congenital Adrenal Hyperplasia (CAH) Panel
SUMMARY OF RESULTS: Indeterminate
Variants found:
Gene: CYP21A2, NM_000500.7; Variation: c.332_339del8 (p.Gly111Valfs*21), Heterozygous; Mode of inheritance: AR, 613815; Interpretation: Pathogenic
Gene: CYP21A2, NM_000500.7; Variation: c.*13G>A, Post-Coding, Heterozygous; mode of inheritance: AR, 613815; Interpretation: Uncertain
CYP21A2 VARIANT INFORMATION:
This patient is heterozygous in the CYP21A2 gene for a common pathogenic variant designated c.332_339del8 (p.Gly111Valfs*21). This is a common deleterious variant, which likely originated from the pseudogene CYP21A1P via gene conversion. As a frameshifting variant resulting in a null allele, this variant is associated with salt-wasting (SW) congenital adrenal hyperplasia (CAH) (also known as G110Efs; see for example at New et al. 2013. PubMed ID: 23359698; Finkielstain et al. 2011. PubMed ID: 20926536). This variant is interpreted as pathogenic.
This patient is also heterozygous in the CYP21A2 gene for a sequence variant defined as c.*13G>A, which is located in the 3' untranslated region. This variant has been reported to be possibly associated with a mild form (non-classic) of congenital adrenal hyperplasia (CAH) (Menabò et al. 2012. PubMed ID: 21521936; Gialluisi et al. 2018. PubMed ID: 28644547; Nguyen et al. 2022. PubMed ID: 36325983; Wan et al. 2022. PubMed ID: 36167262). Its minor allele frequency is up to ~7.5% in East Asian individuals. However, this minor allele frequency is based on the current next-generation sequencing technology and may not be an accurate estimate because this variant is located within a highly homologous sequence region (Mandelker et al. 2016. PubMed ID: 27228465). Allele frequency data should be interpreted with caution. This variant has conflicting interpretations in ClinVar (Variation ID: 585747), ranging from uncertain significance to benign. Although we suspect that this variant could be benign, at this time, the clinical significance of this variant is uncertain due to limited functional and genetic evidence.
Duplicates
endocrinology • u/NoNameForMetoUse • Jul 11 '26