NM_000336.3:c.1789dupC

Variant names:

• chr16-23380661-G-GC
• rs758629218
• NM_000336.3:c.1789dupC

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_000336.3(SCNN1B):​c.1789dupC​(p.Arg597ProfsTer11) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,224 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: SCNN1B NM_000336.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: -0.0680
• Publications: 2 publications found

Genes affected

SCNN1B (HGNC:10600): (sodium channel epithelial 1 subunit beta) Nonvoltage-gated, amiloride-sensitive, sodium channels control fluid and electrolyte transport across epithelia in many organs. These channels are heteromeric complexes consisting of 3 subunits: alpha, beta, and gamma. This gene encodes the beta subunit, and mutations in this gene have been associated with pseudohypoaldosteronism type 1 (PHA1), and Liddle syndrome. [provided by RefSeq, Apr 2009]

SCNN1B Gene-Disease associations (from GenCC):

• Liddle syndrome 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, PanelApp Australia, Labcorp Genetics (formerly Invitae)
• pseudohypoaldosteronism, type IB2, autosomal recessive

  Inheritance: AR Classification: DEFINITIVE Submitted by: Ambry Genetics
• pseudohypoaldosteronism, type IB1, autosomal recessive

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Orphanet, Labcorp Genetics (formerly Invitae)
• Liddle syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• bronchiectasis with or without elevated sweat chloride 1

  Inheritance: SD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Pathogenic. The variant received 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 11 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 16-23380661-G-GC is Pathogenic according to our data. Variant chr16-23380661-G-GC is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 994599.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000336.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCNN1B	NM_000336.3	MANE Select	c.1789dupC	p.Arg597ProfsTer11	frameshift	Exon 13 of 13	NP_000327.2	B2R812
	SCNN1B	NM_001410900.1		c.1681dupC	p.Arg561ProfsTer11	frameshift	Exon 12 of 12	NP_001397829.1	H3BQ95

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SCNN1B	ENST00000343070.7	TSL:1 MANE Select	c.1789dupC	p.Arg597ProfsTer11	frameshift	Exon 13 of 13	ENSP00000345751.2	P51168-1
	SCNN1B	ENST00000307331.9	TSL:5	c.1924dupC	p.Arg642ProfsTer11	frameshift	Exon 14 of 14	ENSP00000302874.5	P51168-2
	SCNN1B	ENST00000962247.1		c.1885dupC	p.Arg629ProfsTer11	frameshift	Exon 13 of 13	ENSP00000632306.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00 AC: 0 AN: 246614 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 1460224 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 726344

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33460

American (AMR) AF: 0.00 AC: 0 AN: 44664

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26072

East Asian (EAS) AF: 0.00 AC: 0 AN: 39682

South Asian (SAS) AF: 0.00 AC: 0 AN: 86186

European-Finnish (FIN) AF: 0.0000569 AC: 3 AN: 52768

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5610

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111464

Other (OTH) AF: 0.00 AC: 0 AN: 60318

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
3	-	-	not provided (3)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.068
Mutation Taster		=1/199	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs758629218; hg19: chr16-23391982; COSMIC: COSV100225805;