17-40779716-G-C

Position:

• chr17-40779716-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_181537.4(KRT27):​c.830C>G​(p.Ala277Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,620 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: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KRT27 NM_181537.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.315

Genes affected

KRT27 (HGNC:30841): (keratin 27) This gene encodes a member of the type I (acidic) keratin family, which belongs to the superfamily of intermediate filament (IF) proteins. Keratins are heteropolymeric structural proteins which form the intermediate filament. These filaments, along with actin microfilaments and microtubules, compose the cytoskeleton of epithelial cells. The type I keratin genes are clustered in a region of chromosome 17q12-q21. [provided by RefSeq, Jul 2009]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3987125).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KRT27	NM_181537.4	c.830C>G	p.Ala277Gly	missense_variant	4/8	ENST00000301656.4	NP_853515.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KRT27	ENST00000301656.4	c.830C>G	p.Ala277Gly	missense_variant	4/8	1	NM_181537.4	ENSP00000301656.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461620 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727100

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

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

May 15, 2024

The c.830C>G (p.A277G) alteration is located in exon 4 (coding exon 4) of the KRT27 gene. This alteration results from a C to G substitution at nucleotide position 830, causing the alanine (A) at amino acid position 277 to be replaced by a glycine (G). 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	0.12
BayesDel_addAF	Uncertain	0.013	T
BayesDel_noAF	Benign	-0.22
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.48	T
Eigen	Uncertain	0.36
Eigen_PC	Uncertain	0.31
FATHMM_MKL	Benign	0.43	N
LIST_S2	Benign	0.74	T
M_CAP	Uncertain	0.088	D
MetaRNN	Benign	0.40	T
MetaSVM	Uncertain	0.58	D
MutationAssessor	Uncertain	2.2	M
PrimateAI	Benign	0.41	T
PROVEAN	Benign	-2.1	N
REVEL	Uncertain	0.44
Sift	Benign	0.030	D
Sift4G	Benign	0.19	T
Polyphen		0.86	P
Vest4		0.23
MutPred		0.40		Loss of stability (P = 0.1381);
MVP		0.68
MPC		0.44
ClinPred		0.88	D
GERP RS		5.5
Varity_R		0.44
gMVP		0.21

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: rs2038294026; hg19: chr17-38935968;