2-232768778-G-T

Variant names:

• chr2-232768778-G-T
• rs387906858
• NM_002242.4:c.496C>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_001172416.1(KCNJ13):​c.260C>A​(p.Ser87*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000069 in 1,448,734 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: KCNJ13 NM_001172416.1 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.45
• Publications: 0 publications found

Genes affected

KCNJ13 (HGNC:6259): (potassium inwardly rectifying channel subfamily J member 13) This gene encodes a member of the inwardly rectifying potassium channel family of proteins. Members of this family form ion channel pores that allow potassium ions to pass into a cell. The encoded protein belongs to a subfamily of low signal channel conductance proteins that have a low dependence on potassium concentration. Mutations in this gene are associated with snowflake vitreoretinal degeneration. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Feb 2010]

GIGYF2 (HGNC:11960): (GRB10 interacting GYF protein 2) This gene contains CAG trinucleotide repeats and encodes a protein containing several stretches of polyglutamine residues. The encoded protein may be involved in the regulation of tyrosine kinase receptor signaling. This gene is located in a chromosomal region that was genetically linked to Parkinson disease type 11, and mutations in this gene were thought to be causative for this disease. However, more recent studies in different populations have been unable to replicate this association. Alternative splicing results in multiple transcript variants. [provided by RefSeq, May 2013]

GIGYF2 Gene-Disease associations (from GenCC):

• Parkinson disease 11, autosomal dominant, susceptibility to

  Inheritance: Unknown, AD Classification: MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 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 0.0877 CDS is truncated, and there are 1 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001172416.1. 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
	KCNJ13	NM_002242.4	MANE Select	c.496C>A	p.Arg166Arg	synonymous	Exon 3 of 3	NP_002233.2	O60928-1
	GIGYF2	NM_001103146.3	MANE Select	c.532+7342G>T		intron	N/A	NP_001096616.1	Q6Y7W6-1
	KCNJ13	NM_001172416.1		c.260C>A	p.Ser87*	stop_gained	Exon 3 of 3	NP_001165887.1	O60928-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNJ13	ENST00000233826.4	TSL:1 MANE Select	c.496C>A	p.Arg166Arg	synonymous	Exon 3 of 3	ENSP00000233826.3	O60928-1
	KCNJ13	ENST00000410029.1	TSL:1	c.496C>A	p.Arg166Arg	synonymous	Exon 2 of 2	ENSP00000386251.1	O60928-1
	GIGYF2	ENST00000373563.9	TSL:1 MANE Select	c.532+7342G>T		intron	N/A	ENSP00000362664.5	Q6Y7W6-1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.90e-7 AC: 1 AN: 1448734 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 718274

⚠️ 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: 33044

American (AMR) AF: 0.00 AC: 0 AN: 43594

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25894

East Asian (EAS) AF: 0.00 AC: 0 AN: 39384

South Asian (SAS) AF: 0.00 AC: 0 AN: 85426

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53252

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5674

European-Non Finnish (NFE) AF: 9.07e-7 AC: 1 AN: 1102718

Other (OTH) AF: 0.00 AC: 0 AN: 59748

⚠️ 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

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.49
CADD	Benign	9.2
DANN	Uncertain	0.99
Eigen	Benign	0.14
Eigen_PC	Benign	0.15
FATHMM_MKL	Uncertain	0.94	D
PhyloP100		2.5
Vest4		0.26
GERP RS		2.7
Mutation Taster		=74/126	disease causing

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

Other links and lift over

dbSNP: rs387906858; hg19: chr2-233633488;