Genetic Variant KRT84:p.Ala540Thr (chr12-52378219-C-T) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_033045.4(KRT84):c.1618G>A(p.Ala540Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000058 in 1,568,826 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A540S) has been classified as Uncertain significance.

Frequency

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

Exomes 𝑓: 0.000061 ( 0 hom. )

Consequence

KRT84
NM_033045.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -4.81

Variant links:

Genes affected

KRT84 (HGNC:6461): (keratin 84) The protein encoded by this gene is a member of the keratin gene family. As a type II hair keratin, it is a basic protein which heterodimerizes with type I keratins to form hair and nails. The type II hair keratins are clustered in a region of chromosome 12q13 and are grouped into two distinct subfamilies based on structure similarity. One subfamily, consisting of KRTHB1, KRTHB3, and KRTHB6, is highly related. The other less-related subfamily includes KRTHB2, KRTHB4, and KRTHB5. All hair keratins are expressed in the hair follicle; this hair keratin is contained primarily in the filiform tongue papilla, among other hair keratins. [provided by RefSeq, Jul 2008]

KRT84 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.030284405).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KRT84	NM_033045.4 link	c.1618G>A	p.Ala540Thr	missense_variant	Exon 9 of 9	ENST00000257951.3	NP_149034.2	Q9NSB2
KRT84	XM_011538335.3 link	c.1618G>A	p.Ala540Thr	missense_variant	Exon 10 of 10		XP_011536637.1	Q9NSB2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KRT84	ENST00000257951.3 link	c.1618G>A	p.Ala540Thr	missense_variant	Exon 9 of 9	1	NM_033045.4	ENSP00000257951.3		Q9NSB2

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152192

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000701

AC:

AN:

171150

Hom.:

AF XY:

0.0000540

AC XY:

AN XY:

92666

show subpopulations

Gnomad AFR exome

AF:

0.000105

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000741

Gnomad SAS exome

AF:

0.000127

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000999

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000607

AC:

AN:

1416516

Hom.:

Cov.:

AF XY:

0.0000571

AC XY:

AN XY:

700708

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000266

Gnomad4 SAS exome

AF:

0.0000749

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000706

Gnomad4 OTH exome

AF:

0.0000170

GnomAD4 genome

AF:

0.0000328

AC:

AN:

152310

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74478

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000567

ExAC

AF:

0.0000424

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Dec 02, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1618G>A (p.A540T) alteration is located in exon 9 (coding exon 9) of the KRT84 gene. This alteration results from a G to A substitution at nucleotide position 1618, causing the alanine (A) at amino acid position 540 to be replaced by a threonine (T). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.070

BayesDel_addAF

Benign

-0.27

BayesDel_noAF

Benign

-0.63

CADD

Benign

0.0040

DANN

Benign

0.56

DEOGEN2

Benign

0.010

Eigen

Benign

-1.9

Eigen_PC

Benign

-2.0

FATHMM_MKL

Benign

0.0042

LIST_S2

Benign

0.28

M_CAP

Benign

0.0071

MetaRNN

Benign

0.030

MetaSVM

Benign

-0.90

MutationAssessor

Benign

-0.69

PrimateAI

Benign

0.35

PROVEAN

Benign

0.21

REVEL

Benign

0.17

Sift

Benign

0.33

Sift4G

Benign

0.53

Polyphen

0.0010

Vest4

0.054

MutPred

0.26

Gain of catalytic residue at G536 (P = 0.0037);

MVP

0.14

MPC

0.027

ClinPred

0.017

GERP RS

-3.9

Varity_R

0.032

gMVP

0.18

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

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