2-232766324-A-G

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_Strong BS1_Supporting

The NM_002242.4(KCNJ13):c.*1867T>C variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000131 in 205,964 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000098 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00022 (0 hom.)
• Consequence: KCNJ13 NM_002242.4 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.06

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]

(HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.92).
• BS1: Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.0000985 (15/152346) while in subpopulation EAS AF= 0.0027 (14/5190). AF 95% confidence interval is 0.00163. There are 0 homozygotes in gnomad4. There are 8 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNJ13	NM_002242.4	c.*1867T>C		3_prime_UTR_variant	3/3	ENST00000233826.4
GIGYF2	NM_001103146.3	c.532+4888A>G		intron_variant		ENST00000373563.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNJ13	ENST00000233826.4	c.*1867T>C		3_prime_UTR_variant	3/3	1	NM_002242.4	P1
GIGYF2	ENST00000373563.9	c.532+4888A>G		intron_variant		1	NM_001103146.3	P4
	ENST00000427571.1	n.271+1355T>C		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes AF: 0.0000985 AC: 15 AN: 152228 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00269

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.000478

GnomAD4 exome AF: 0.000224 AC: 12 AN: 53618 Hom.: 0 AF XY: 0.000211 AC XY: 6 AN XY: 28462

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00503

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000985 AC: 15 AN: 152346 Hom.: 0 Cov.: 32 AF XY: 0.000107 AC XY: 8 AN XY: 74506

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00270

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.000473

Bravo AF: 0.0000680

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Leber congenital amaurosis 16 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.92
Cadd	Benign	0.17
Dann	Benign	0.42

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: rs144253492; hg19: chr2-233631034;