19-50907077-CAG-C

Variant summary

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

The NM_004917.5(KLK4):c.620_621del(p.Ser207TrpfsTer38) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000205 in 1,461,808 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: KLK4 NM_004917.5 frameshift
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.53

Genes affected

KLK4 (HGNC:6365): (kallikrein related peptidase 4) Kallikreins are a subgroup of serine proteases having diverse physiological functions. Growing evidence suggests that many kallikreins are implicated in carcinogenesis and some have potential as novel cancer and other disease biomarkers. This gene is one of the fifteen kallikrein subfamily members located in a cluster on chromosome 19. In some tissues its expression is hormonally regulated. The expression pattern of a similar mouse protein in murine developing teeth supports a role for the protein in the degradation of enamel proteins. Several transcript variants encoding different proteins have been found for this gene. [provided by RefSeq, Dec 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 is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.19 CDS is truncated, and there are 1 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-50907077-CAG-C is Pathogenic according to our data. Variant chr19-50907077-CAG-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1299354.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KLK4	NM_004917.5	c.620_621del	p.Ser207TrpfsTer38	frameshift_variant	6/6	ENST00000324041.6
KLK4	NM_001302961.2	c.335_336del	p.Ser112TrpfsTer38	frameshift_variant	5/5
KLK4	NR_126566.2	n.609_610del		non_coding_transcript_exon_variant	5/5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KLK4	ENST00000324041.6	c.620_621del	p.Ser207TrpfsTer38	frameshift_variant	6/6	1	NM_004917.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250874 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135760

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 SAS exome AF: 0.0000327

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: 1461808 Hom.: 0 AF XY: 0.00000413 AC XY: 3 AN XY: 727196

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: 0.0000348

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Amelogenesis imperfecta type 2A1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Genetic Diagnostics Department, Viafet Genomics Laboratory

Aug 23, 2021

As part of Carrier Screening testing performed at Viafet Genomics Laboratory, this variant was identified in a heterozygous state in a patient who is not affected with this condition. This variant is present in exon 5/5 in a position that is conserved across both transcripts of this gene (2/2). A loss-of-function variant is reported as disease-causing in HGMD and ClinVar after this position. In addition, this variant has been identified in a homozygous state in a patient affected with Amelogenesis Imperfecta. In vitro expression of the mutant protein has revealed a great reduction in protein level and absence of proteolytic activity compared to the wildtype (PMID: 26124219). -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs768235705; hg19: chr19-51410333;