rs994764994

Positions:

• chr6-32040188-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP3_Strong PP5

The NM_000500.9(CYP21A2):​c.922T>G​(p.Leu308Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,544 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CYP21A2 NM_000500.9 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 0.456

Genes affected

CYP21A2 (HGNC:2600): (cytochrome P450 family 21 subfamily A member 2) This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum and hydroxylates steroids at the 21 position. Its activity is required for the synthesis of steroid hormones including cortisol and aldosterone. Mutations in this gene cause congenital adrenal hyperplasia. A related pseudogene is located near this gene; gene conversion events involving the functional gene and the pseudogene are thought to account for many cases of steroid 21-hydroxylase deficiency. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a helix (size 31) in uniprot entity CP21A_HUMAN there are 17 pathogenic changes around while only 1 benign (94%) in NM_000500.9
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.968
• PP5: Variant 6-32040188-T-G is Pathogenic according to our data. Variant chr6-32040188-T-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 585757.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CYP21A2	NM_000500.9	c.922T>G	p.Leu308Val	missense_variant	7/10	ENST00000644719.2	NP_000491.4
CYP21A2	NM_001128590.4	c.832T>G	p.Leu278Val	missense_variant	6/9		NP_001122062.3
CYP21A2	NM_001368143.2	c.517T>G	p.Leu173Val	missense_variant	7/10		NP_001355072.1
CYP21A2	NM_001368144.2	c.517T>G	p.Leu173Val	missense_variant	6/9		NP_001355073.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CYP21A2	ENST00000644719.2	c.922T>G	p.Leu308Val	missense_variant	7/10		NM_000500.9	ENSP00000496625	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000162 AC: 4 AN: 246400 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 134266

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000116

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460544 Hom.: 0 Cov.: 38 AF XY: 0.00 AC XY: 0 AN XY: 726596

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000671

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.0000189

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Athena Diagnostics

Feb 14, 2018

- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jun 13, 2023

Variant summary: CYP21A2 c.922T>G (p.Leu308Val) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.6e-05 in 246400 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.922T>G has been reported in the literature in individuals affected with Congenital Adrenal Hyperplasia (CAH), including at least one individual with simple virilizing CAH (e.g., Sarafoglou_Pediatrics_2012, Sarafoglou_JAMA_2012) and at least two individuals with non-classic CAH (e.g., New_2013, Bruque_2013, Wan_2023). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 27966633, 23359698, 23071209, 36167262, 22692165). One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation and classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Uncertain	0.082	D
BayesDel_noAF	Uncertain	0.11
CADD	Benign	20
DANN	Uncertain	1.0
Eigen	Benign	0.11
Eigen_PC	Benign	-0.065
FATHMM_MKL	Uncertain	0.83	D
M_CAP	Uncertain	0.18	D
MetaRNN	Pathogenic	0.97	D;D;D;D
MetaSVM	Uncertain	0.24	D
MutationTaster	Benign	0.68	D;D
PrimateAI	Uncertain	0.63	T
PROVEAN	Uncertain	-2.7	D;.;D;.
REVEL	Pathogenic	0.71
Sift	Uncertain	0.0020	D;.;D;.
Sift4G	Uncertain	0.0050	D;.;D;.
Polyphen		1.0	D;D;.;D
Vest4		0.56
MutPred		0.90		Loss of stability (P = 0.168);Loss of stability (P = 0.168);.;Loss of stability (P = 0.168);
MVP		0.96
MPC		1.4
ClinPred		0.91	D
GERP RS		-0.53
gMVP		0.82

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs994764994; hg19: chr6-32007965;