Genetic Variant KRT33A:p.Ser308Ile (chr17-41346622-C-A) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_004138.4(KRT33A):c.923G>T(p.Ser308Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,614,144 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KRT33A
NM_004138.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.622

Variant links:

Genes affected

KRT33A (HGNC:6450): (keratin 33A) This gene encodes a member of the keratin gene family. This gene is one of multiple type I hair keratin genes that are clustered in a region of chromosome 17q12-q21 and have the same direction of transcription. As a type I hair keratin, the encoded protein is an acidic protein which heterodimerizes with type II keratins to form hair and nails. There are two isoforms of this protein, encoded by two separate genes, keratin 33A and keratin 33B. [provided by RefSeq, May 2012]

KRT33A links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KRT33A	NM_004138.4 link	c.923G>T	p.Ser308Ile	missense_variant	Exon 6 of 7	ENST00000007735.4	NP_004129.2	O76009
KRT33A	XM_011524786.4 link	c.446G>T	p.Ser149Ile	missense_variant	Exon 4 of 5		XP_011523088.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KRT33A	ENST00000007735.4 link	c.923G>T	p.Ser308Ile	missense_variant	Exon 6 of 7	1	NM_004138.4	ENSP00000007735.3		O76009

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152256

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000965

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:

0.00000398

AC:

AN:

251448

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135910

show subpopulations

Gnomad AFR exome

AF:

0.0000615

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:

6.84e-7

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727244

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

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:

0.00

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152256

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74382

show subpopulations

Gnomad4 AFR

AF:

0.0000965

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:

0.0000151

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jan 02, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.923G>T (p.S308I) alteration is located in exon 6 (coding exon 6) of the KRT33A gene. This alteration results from a G to T substitution at nucleotide position 923, causing the serine (S) at amino acid position 308 to be replaced by an isoleucine (I). 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

Uncertain

0.38

BayesDel_addAF

Benign

-0.0034

BayesDel_noAF

Uncertain

-0.060

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.73

Eigen

Uncertain

0.33

Eigen_PC

Uncertain

0.24

FATHMM_MKL

Benign

0.67

M_CAP

Uncertain

0.096

MetaRNN

Uncertain

0.47

MetaSVM

Pathogenic

0.90

MutationAssessor

Pathogenic

3.4

PrimateAI

Uncertain

0.52

PROVEAN

Pathogenic

-5.2

REVEL

Uncertain

0.55

Sift

Uncertain

0.0080

Sift4G

Uncertain

0.029

Polyphen

0.74

Vest4

0.46

MutPred

0.53

Loss of phosphorylation at S308 (P = 0.029);

MVP

0.44

MPC

0.59

ClinPred

0.97

GERP RS

4.5

Varity_R

0.91

gMVP

0.47

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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