3-42685722-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_152393.4(KLHL40):c.104G>A(p.Cys35Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,790 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 (★). Synonymous variant affecting the same amino acid position (i.e. C35C) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KLHL40 NM_152393.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.52

Genes affected

KLHL40 (HGNC:30372): (kelch like family member 40) This gene encodes a protein containing a BACK domain, a BTB/POZ domain, and 5 Kelch repeats, however, its exact function is not known. The gene and the multi-domain protein structure are conserved across different taxa, including primates, rodents, chicken and zebrafish. [provided by RefSeq, Dec 2012]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a domain BTB (size 65) in uniprot entity KLH40_HUMAN there are 5 pathogenic changes around while only 2 benign (71%) in NM_152393.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.896

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KLHL40	NM_152393.4	c.104G>A	p.Cys35Tyr	missense_variant	1/6	ENST00000287777.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KLHL40	ENST00000287777.5	c.104G>A	p.Cys35Tyr	missense_variant	1/6	1	NM_152393.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460790 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726724

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Nemaline myopathy 8 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 01, 2021

This sequence change replaces cysteine with tyrosine at codon 35 of the KLHL40 protein (p.Cys35Tyr). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and tyrosine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with KLHL40-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.82
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
Cadd	Pathogenic	29
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.53	D
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Benign	0.72	T
M_CAP	Uncertain	0.20	D
MetaRNN	Pathogenic	0.90	D
MetaSVM	Uncertain	0.34	D
MutationAssessor	Uncertain	2.4	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.89	D
PROVEAN	Pathogenic	-5.4	D
REVEL	Pathogenic	0.75
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0040	D
Polyphen		1.0	D
Vest4		0.89
MutPred		0.66		Gain of phosphorylation at C35 (P = 0.0665);
MVP		0.83
MPC		2.2
ClinPred		1.0	D
GERP RS		4.7
Varity_R		0.94
gMVP		0.89

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: rs866611021; hg19: chr3-42727214;