18-63782420-CAG-C

Position:

• chr18-63782420-CAG-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_003784.4(SERPINB7):​c.54_55del​(p.Glu18AspfsTer3) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,826 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: 0.0000014 (0 hom.)
• Consequence: SERPINB7 NM_003784.4 frameshift
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 0.673

Genes affected

SERPINB7 (HGNC:13902): (serpin family B member 7) This gene encodes a member of a family of proteins which function as protease inhibitors. Expression of this gene is upregulated in IgA nephropathy and mutations have been found to cause palmoplantar keratoderma, Nagashima type. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jun 2014]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 18-63782420-CAG-C is Pathogenic according to our data. Variant chr18-63782420-CAG-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3049966.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SERPINB7	NM_003784.4	c.54_55del	p.Glu18AspfsTer3	frameshift_variant	2/8	ENST00000398019.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SERPINB7	ENST00000398019.7	c.54_55del	p.Glu18AspfsTer3	frameshift_variant	2/8	1	NM_003784.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461826 Hom.: 0 AF XY: 0.00000275 AC XY: 2 AN XY: 727202

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

SERPINB7-related disorder Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Jan 04, 2024

The SERPINB7 c.54_55delGA variant is predicted to result in a frameshift and premature protein termination (p.Glu18Aspfs*3). To our knowledge, this variant has not been reported in the literature or in a large population database, indicating this variant is rare. Frameshift variants in SERPINB7 are expected to be pathogenic. This variant is interpreted as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

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: rs1049876333; hg19: chr18-61449654;