chr6-32039178-C-G

Position:

• chr6-32039178-C-G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP3_Strong PP5_Moderate

The NM_001368143.2(CYP21A2):​c.-29C>G variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: CYP21A2 NM_001368143.2 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 2.26

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 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: BayesDel_addAF computational evidence supports a deleterious effect, 0.575
• PP5: Variant 6-32039178-C-G is Pathogenic according to our data. Variant chr6-32039178-C-G is described in ClinVar as [Pathogenic]. Clinvar id is 375321.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr6-32039178-C-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CYP21A2	NM_000500.9	c.377C>G	p.Ser126*	stop_gained	3/10	ENST00000644719.2	NP_000491.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CYP21A2	ENST00000644719.2	c.377C>G	p.Ser126*	stop_gained	3/10		NM_000500.9	ENSP00000496625.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 77

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 16, 2021

The frequency data for this variant in the population databases (ExAC) is considered unreliable due to the presence of homologous sequence, such as pseudogenes or paralogs, in the genome. For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in CYP21A2 are known to be pathogenic (PMID: 10857554). This variant has been observed in individuals with classic salt-wasting congenital adrenal hyperplasia due to 21-hydroxylase deficiency (PMID: 30048636, 31446012). ClinVar contains an entry for this variant (Variation ID: 375321). This sequence change creates a premature translational stop signal (p.Ser126*) in the CYP21A2 gene. It is expected to result in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	35
DANN	Uncertain	1.0
Eigen	Pathogenic	0.84
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Benign	0.63	D
Vest4		0.89
GERP RS		4.8

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: rs1057519069; hg19: chr6-32006955;