Genetic Variant NM_001126128.2:c.297delT (chr3-71772816-CA-C) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_StrongPM2

The NM_001126128.2(PROK2):c.297delT(p.Phe99LeufsTer28) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000806 in 1,613,858 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

PROK2
NM_001126128.2 frameshift

Scores

Not classified

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: -1.95

Variant links:

Genes affected

PROK2 (HGNC:18455): (prokineticin 2) This gene encodes a protein expressed in the suprachiasmatic nucleus (SCN) circadian clock that may function as the output component of the circadian clock. The secreted form of the encoded protein may also serve as a chemoattractant for neuronal precursor cells in the olfactory bulb. Proteins from other vertebrates which are similar to this gene product were isolated based on homology to snake venom and secretions from frog skin, and have been shown to have diverse functions. Mutations in this gene are associated with Kallmann syndrome 4. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

PROK2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 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 0.238 CDS is truncated, and there are 0 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PROK2	NM_001126128.2 link	c.297delT	p.Phe99LeufsTer28	frameshift_variant	Exon 4 of 4	ENST00000295619.4	NP_001119600.1	Q9HC23-1
PROK2	NM_021935.4 link	c.234delT	p.Phe78LeufsTer28	frameshift_variant	Exon 3 of 3		NP_068754.1	Q9HC23-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PROK2	ENST00000295619.4 link	c.297delT	p.Phe99LeufsTer28	frameshift_variant	Exon 4 of 4	1	NM_001126128.2	ENSP00000295619.3		Q9HC23-1
PROK2	ENST00000353065.7 link	c.234delT	p.Phe78LeufsTer28	frameshift_variant	Exon 3 of 3	1		ENSP00000295618.3		Q9HC23-2

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152060

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000119

AC:

AN:

251124

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135778

show subpopulations

Gnomad AFR exome

AF:

0.000185

Gnomad AMR exome

AF:

0.00

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:

0.00000547

AC:

AN:

1461798

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727198

show subpopulations

Gnomad4 AFR exome

AF:

0.000209

Gnomad4 AMR exome

AF:

0.00

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:

0.0000166

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152060

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74292

show subpopulations

Gnomad4 AFR

AF:

0.000121

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000416

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Oct 19, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.297delT (p.F99Lfs*28) alteration, located in exon 4 (coding exon 4) of the PROK2 gene, consists of a deletion of one nucleotide at position 297, causing a translational frameshift with a predicted alternate stop codon after 28 amino acids. This alteration occurs at the 3' terminus of the PROK2 gene, is not expected to trigger nonsense-mediated mRNA decay, and only impacts the last 24% of the protein. The exact functional effect of this alteration is unknown. Based on data from gnomAD, this allele has an overall frequency of 0.002% (5/282370) total alleles studied. The highest observed frequency was 0.020% (5/24864) of African alleles. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

PROK2-related disorder

Uncertain:1

Sep 02, 2022

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The PROK2 c.297delT variant is predicted to result in a frameshift and premature protein termination (p.Phe99Leufs*28). To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.020% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/3-71821967-CA-C). A limited number of loss-of-function variants have been reported in this gene in association with disease to date (Human Gene Mutation Database; http://www.hgmd.cf.ac.uk/ac/index.php); however, loss-of-function variants have also been reported in general population databases (see, for example, https://gnomad.broadinstitute.org/variant/3-71821967-C-CA?dataset=gnomad_r2_1). Although we suspect that this variant may be pathogenic, possibly for an autosomal recessive form of disease, the clinical significance of this variant is currently classified as uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over