3-42686586-T-G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_152393.4(KLHL40):​c.968T>G​(p.Ile323Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000652 in 1,614,064 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: 𝑓 0.00037 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00068 ( 0 hom. )

Consequence

KLHL40
NM_152393.4 missense

Scores

2
8
9

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 8.02

Publications

3 publications found
Variant links:
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]
KLHL40 Gene-Disease associations (from GenCC):
  • nemaline myopathy 8
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics, G2P
  • severe congenital nemaline myopathy
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.106862426).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KLHL40NM_152393.4 linkc.968T>G p.Ile323Ser missense_variant Exon 1 of 6 ENST00000287777.5 NP_689606.2 Q2TBA0-1A8K5H9

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KLHL40ENST00000287777.5 linkc.968T>G p.Ile323Ser missense_variant Exon 1 of 6 1 NM_152393.4 ENSP00000287777.4 Q2TBA0-1

Frequencies

GnomAD3 genomes
AF:
0.000375
AC:
57
AN:
152112
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000966
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000196
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.0000943
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000720
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000406
AC:
102
AN:
251450
AF XY:
0.000383
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.000116
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000139
Gnomad NFE exome
AF:
0.000791
Gnomad OTH exome
AF:
0.000651
GnomAD4 exome
AF:
0.000681
AC:
995
AN:
1461834
Hom.:
0
Cov.:
30
AF XY:
0.000650
AC XY:
473
AN XY:
727220
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.000201
AC:
9
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.000169
AC:
9
AN:
53366
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.000857
AC:
953
AN:
1112010
Other (OTH)
AF:
0.000364
AC:
22
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.476
Heterozygous variant carriers
0
58
116
174
232
290
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
42
84
126
168
210
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.000374
AC:
57
AN:
152230
Hom.:
0
Cov.:
33
AF XY:
0.000349
AC XY:
26
AN XY:
74424
show subpopulations
African (AFR)
AF:
0.0000963
AC:
4
AN:
41536
American (AMR)
AF:
0.000196
AC:
3
AN:
15298
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4812
European-Finnish (FIN)
AF:
0.0000943
AC:
1
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000721
AC:
49
AN:
68002
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
3
6
10
13
16
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.000620
Hom.:
1
Bravo
AF:
0.000423
TwinsUK
AF:
0.00162
AC:
6
ALSPAC
AF:
0.00104
AC:
4
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000814
AC:
7
ExAC
AF:
0.000420
AC:
51
EpiCase
AF:
0.000709
EpiControl
AF:
0.000474

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:3
Feb 11, 2022
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 27, 2023
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

-
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The KLHL40 p.Ile323Ser variant was not identified in the literature but was identified in dbSNP (ID: rs146161469) and ClinVar (classified as uncertain significance by Invitae for Nemaline myopathy 8 and GeneDx). The variant was identified in control databases in 108 of 282838 chromosomes at a frequency of 0.0003818 increasing the likelihood this could be a low frequency benign variant (Genome Aggregation Database March 6, 2019, v2.1.1). The variant was observed in the following populations: European (non-Finnish) in 96 of 129144 chromosomes (freq: 0.000743), Other in 4 of 7226 chromosomes (freq: 0.000554), European (Finnish) in 3 of 25124 chromosomes (freq: 0.000119), Latino in 4 of 35440 chromosomes (freq: 0.000113) and African in 1 of 24966 chromosomes (freq: 0.00004), but was not observed in the Ashkenazi Jewish, East Asian, or South Asian populations. Although the p.Ile323 residue is not conserved in mammals and other organisms, computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) suggest that the variant may impact the protein. The variant occurs outside of the splicing consensus sequence and 1 of 4 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) predict a greater than 10% difference in splicing; this is not very predictive of pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -

not specified Uncertain:1
Mar 28, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: KLHL40 c.968T>G (p.Ile323Ser) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00041 in 251450 control chromosomes (gnomAD). To our knowledge, no occurrence of c.968T>G in individuals affected with Nemaline Myopathy 8 and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 279825). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Nemaline myopathy 8 Uncertain:1
Jan 02, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 323 of the KLHL40 protein (p.Ile323Ser). This variant is present in population databases (rs146161469, gnomAD 0.07%). This variant has not been reported in the literature in individuals affected with KLHL40-related conditions. ClinVar contains an entry for this variant (Variation ID: 279825). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on KLHL40 protein function. 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
0.81
BayesDel_addAF
Benign
-0.24
T
BayesDel_noAF
Benign
-0.14
CADD
Uncertain
25
DANN
Uncertain
0.99
DEOGEN2
Benign
0.22
T
Eigen
Uncertain
0.25
Eigen_PC
Uncertain
0.37
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.89
D
M_CAP
Benign
0.059
D
MetaRNN
Benign
0.11
T
MetaSVM
Benign
-0.43
T
MutationAssessor
Uncertain
2.4
M
PhyloP100
8.0
PrimateAI
Benign
0.43
T
PROVEAN
Uncertain
-2.4
N
REVEL
Uncertain
0.40
Sift
Benign
0.15
T
Sift4G
Uncertain
0.0030
D
Polyphen
0.16
B
Vest4
0.43
MVP
0.76
MPC
0.15
ClinPred
0.14
T
GERP RS
5.1
Varity_R
0.58
gMVP
0.77
Mutation Taster
=31/69
disease causing

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

Other links and lift over

dbSNP: rs146161469; hg19: chr3-42728078; API