chr17-41346505-G-T

Position:

• chr17-41346505-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The ENST00000007735.4(KRT33A):​c.1040C>A​(p.Ala347Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,814 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: KRT33A ENST00000007735.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.73

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.752

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KRT33A	NM_004138.4	c.1040C>A	p.Ala347Glu	missense_variant	6/7	ENST00000007735.4	NP_004129.2
KRT33A	XM_011524786.4	c.563C>A	p.Ala188Glu	missense_variant	4/5		XP_011523088.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KRT33A	ENST00000007735.4	c.1040C>A	p.Ala347Glu	missense_variant	6/7	1	NM_004138.4	ENSP00000007735	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461814 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727204

Gnomad4 AFR exome AF: 0.00

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: 0.00000270

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 01, 2023

The c.1040C>A (p.A347E) alteration is located in exon 6 (coding exon 6) of the KRT33A gene. This alteration results from a C to A substitution at nucleotide position 1040, causing the alanine (A) at amino acid position 347 to be replaced by a glutamic acid (E). 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	0.53
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.040
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.53	D
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Uncertain	0.93	D
M_CAP	Uncertain	0.10	D
MetaRNN	Pathogenic	0.75	D
MetaSVM	Uncertain	0.43	D
MutationAssessor	Uncertain	2.6	M
MutationTaster	Benign	0.90	N
PrimateAI	Uncertain	0.50	T
PROVEAN	Pathogenic	-4.5	D
REVEL	Uncertain	0.48
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0020	D
Polyphen		0.99	D
Vest4		0.59
MutPred		0.57		Gain of disorder (P = 0.0151);
MVP		0.32
MPC		0.67
ClinPred		1.0	D
GERP RS		4.5
Varity_R		0.86
gMVP		0.59

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: rs548761610; hg19: chr17-39502757; COSMIC: COSV50371352;