17-40861690-G-C

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The NM_000223.4(KRT12):c.1456C>G(p.Gln486Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,613,148 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000027 (0 hom.)
• Consequence: KRT12 NM_000223.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.31

Genes affected

KRT12 (HGNC:6414): (keratin 12) KRT12 encodes the type I intermediate filament chain keratin 12, expressed in corneal epithelia. Mutations in this gene lead to Meesmann corneal dystrophy. [provided by RefSeq, Jul 2008]

(HGNC:):

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.040653825).
• BS1: Variant frequency is greater than expected in population amr. gnomad4_exome allele frequency = 0.0000267 (39/1460818) while in subpopulation AMR AF= 0.000157 (7/44724). AF 95% confidence interval is 0.0000728. There are 0 homozygotes in gnomad4_exome. There are 20 alleles in male gnomad4_exome subpopulation. Median coverage is 29. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High AC in GnomAdExome at 16 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KRT12	NM_000223.4	c.1456C>G	p.Gln486Glu	missense_variant	8/8	ENST00000251643.5
LOC105371777	XR_934754.3	n.63+10830G>C		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KRT12	ENST00000251643.5	c.1456C>G	p.Gln486Glu	missense_variant	8/8	1	NM_000223.4	P1
	ENST00000579136.1	n.62-1396G>C		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152212 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.000288

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000638 AC: 16 AN: 250882 Hom.: 0 AF XY: 0.0000590 AC XY: 8 AN XY: 135704

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000202

Gnomad ASJ exome AF: 0.000794

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000883

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000267 AC: 39 AN: 1460818 Hom.: 0 Cov.: 29 AF XY: 0.0000275 AC XY: 20 AN XY: 726784

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000157

Gnomad4 ASJ exome AF: 0.000804

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.0000828

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152330 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74494

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000653

Gnomad4 ASJ AF: 0.000288

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000501 Hom.: 0

Bravo AF: 0.0000378

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.0000247 AC: 3

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 07, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Not Available"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with KRT12-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces glutamine, which is neutral and polar, with glutamic acid, which is acidic and polar, at codon 486 of the KRT12 protein (p.Gln486Glu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.069
BayesDel_addAF	Benign	-0.27	T
BayesDel_noAF	Benign	-0.34
Cadd	Benign	20
Dann	Uncertain	0.98
DEOGEN2	Benign	0.12	T;T
Eigen	Benign	-0.085
Eigen_PC	Benign	0.12
FATHMM_MKL	Uncertain	0.91	D
M_CAP	Benign	0.015	T
MetaRNN	Benign	0.041	T;T
MetaSVM	Benign	-0.71	T
MutationAssessor	Benign	1.3	L;L
MutationTaster	Benign	0.94	N
PrimateAI	Benign	0.33	T
Polyphen		0.0030	B;B
Vest4		0.16
MVP		0.86
MPC		.;8.64925113599E-4
ClinPred		0.073	T
GERP RS		4.6
Varity_R		0.15
gMVP		0.52

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: rs186050235; hg19: chr17-39017942;