Genetic Variant KLHL20:p.Thr107Ala (chr1-173734008-A-G) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_014458.4(KLHL20):c.319A>G(p.Thr107Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KLHL20
NM_014458.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 9.20

Publications

0 publications found

Variant links:

Genes affected

KLHL20 (HGNC:25056): (kelch like family member 20) The protein encoded by this gene is a member of the kelch family of proteins, which is characterized by a 44-56 amino acid repeat motif. The kelch motif appears in many different polypeptide contexts and contains multiple potential protein-protein contact sites. Members of this family are present both throughout the cell and extracellularly, with diverse activities. [provided by RefSeq, Jul 2008]

KLHL20 Gene-Disease associations (from GenCC):

neurodevelopmental disorder
Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics
complex neurodevelopmental disorder
Inheritance: AD Classification: MODERATE Submitted by: G2P

KLHL20 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KLHL20	NM_014458.4 link	c.319A>G	p.Thr107Ala	missense_variant	Exon 3 of 12	ENST00000209884.5	NP_055273.2	Q9Y2M5-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
KLHL20	ENST00000209884.5 link	c.319A>G	p.Thr107Ala	missense_variant	Exon 3 of 12	1	NM_014458.4	ENSP00000209884.4	Q9Y2M5-1
KLHL20	ENST00000483154.5 link	n.712A>G		non_coding_transcript_exon_variant	Exon 3 of 3	1
KLHL20	ENST00000493170.1 link	n.448A>G		non_coding_transcript_exon_variant	Exon 3 of 3	1
KLHL20	ENST00000479505.5 link	n.*180A>G		downstream_gene_variant		2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461894

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727248

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1112012

Other (OTH)

AF:

0.00

AC:

AN:

60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Feb 08, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.319A>G (p.T107A) alteration is located in exon 3 (coding exon 2) of the KLHL20 gene. This alteration results from a A to G substitution at nucleotide position 319, causing the threonine (T) at amino acid position 107 to be replaced by an alanine (A). 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

0.25

BayesDel_addAF

Uncertain

0.047

BayesDel_noAF

Benign

-0.17

CADD

Benign

(source)

DANN

Benign

0.97

DEOGEN2

Benign

0.24

Eigen

Benign

0.074

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.94

M_CAP

Benign

0.011

MetaRNN

Uncertain

0.42

MetaSVM

Benign

-0.99

MutationAssessor

Benign

1.2

PhyloP100

9.2

PrimateAI

Pathogenic

0.82

PROVEAN

Benign

-1.5

REVEL

Benign

0.21

Sift

Benign

0.27

Sift4G

Benign

0.64

Polyphen

0.0020

Vest4

0.70

MutPred

0.40

Loss of phosphorylation at T107 (P = 0.0675);

MVP

0.74

MPC

0.86

ClinPred

0.53

GERP RS

5.6

Varity_R

0.15

gMVP

0.53

Mutation Taster

=31/69

disease causing

(source)

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

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1-173734008-A-G

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over