3-49172830-C-T

Variant names:

• chr3-49172830-C-T
• rs946616957
• NM_173546.3:c.61C>T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2 PP3_Moderate BS2_Supporting

The NM_173546.3(KLHDC8B):​c.61C>T​(p.Arg21Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,756 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: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: KLHDC8B NM_173546.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.84

Genes affected

KLHDC8B (HGNC:28557): (kelch domain containing 8B) This gene encodes a protein which forms a distinct beta-propeller protein structure of kelch domains allowing for protein-protein interactions. Mutations in this gene have been associated with Hodgkin lymphoma. [provided by RefSeq, Sep 2010]

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, 0.842
• BS2: High AC in GnomAdExome4 at 5 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KLHDC8B	NM_173546.3	c.61C>T	p.Arg21Trp	missense_variant	Exon 2 of 6	ENST00000332780.4	NP_775817.1
KLHDC8B	XM_006713015.4	c.61C>T	p.Arg21Trp	missense_variant	Exon 2 of 6		XP_006713078.1
KLHDC8B	XM_006713016.4	c.61C>T	p.Arg21Trp	missense_variant	Exon 2 of 6		XP_006713079.1
KLHDC8B	XM_005264938.4	c.61C>T	p.Arg21Trp	missense_variant	Exon 2 of 6		XP_005264995.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KLHDC8B	ENST00000332780.4	c.61C>T	p.Arg21Trp	missense_variant	Exon 2 of 6	1	NM_173546.3	ENSP00000327468.2
KLHDC8B	ENST00000476495.2	n.118C>T		non_coding_transcript_exon_variant	Exon 1 of 3	2
KLHDC8B	ENST00000459846.6	n.230+29C>T		intron_variant	Intron 2 of 4	3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461756 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727188

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: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Apr 20, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.61C>T (p.R21W) alteration is located in exon 2 (coding exon 1) of the KLHDC8B gene. This alteration results from a C to T substitution at nucleotide position 61, causing the arginine (R) at amino acid position 21 to be replaced by a tryptophan (W). 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	Pathogenic	0.77
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.45	T
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.91	D
M_CAP	Uncertain	0.22	D
MetaRNN	Pathogenic	0.84	D
MetaSVM	Uncertain	0.70	D
MutationAssessor	Pathogenic	4.1	H
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-5.3	D
REVEL	Pathogenic	0.84
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.43
MutPred		0.88		Gain of glycosylation at Y23 (P = 0.032);
MVP		0.95
MPC		1.3
ClinPred		1.0	D
GERP RS		5.3
Varity_R		0.83
gMVP		0.88

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs946616957; hg19: chr3-49210263;