rs376452959

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_001079802.2(FKTN):c.293C>G(p.Thr98Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,612,598 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T98A) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

FKTN
NM_001079802.2 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.435

Variant links:

Genes affected

FKTN (HGNC:3622): (fukutin) The protein encoded by this gene is a putative transmembrane protein that is localized to the cis-Golgi compartment, where it may be involved in the glycosylation of alpha-dystroglycan in skeletal muscle. The encoded protein is thought to be a glycosyltransferase and could play a role in brain development. Defects in this gene are a cause of Fukuyama-type congenital muscular dystrophy (FCMD), Walker-Warburg syndrome (WWS), limb-girdle muscular dystrophy type 2M (LGMD2M), and dilated cardiomyopathy type 1X (CMD1X). Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Nov 2010]

FKTN links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.03816876).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FKTN	NM_001079802.2 linkuse as main transcript	c.293C>G	p.Thr98Ser	missense_variant	5/11	ENST00000357998.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FKTN	ENST00000357998.10 linkuse as main transcript	c.293C>G	p.Thr98Ser	missense_variant	5/11	5	NM_001079802.2	P1	O75072-1

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152188

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000965

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000359

AC:

AN:

250764

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135580

show subpopulations

Gnomad AFR exome

AF:

0.000308

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000103

AC:

AN:

1460410

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

726564

show subpopulations

Gnomad4 AFR exome

AF:

0.000269

Gnomad4 AMR exome

AF:

0.0000894

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:

0.0000331

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152188

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74346

show subpopulations

Gnomad4 AFR

AF:

0.0000965

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000945

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000330

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Walker-Warburg congenital muscular dystrophy

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Sep 01, 2022	This sequence change replaces threonine, which is neutral and polar, with serine, which is neutral and polar, at codon 98 of the FKTN protein (p.Thr98Ser). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with FKTN-related conditions. ClinVar contains an entry for this variant (Variation ID: 459221). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -
Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Oct 28, 2019	- -

FKTN-related condition

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Oct 31, 2023

The FKTN c.293C>G variant is predicted to result in the amino acid substitution p.Thr98Ser. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.024% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/9-108363553-C-G). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Revvity Omics, Revvity

Jan 06, 2021

- -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 15, 2022

The p.T98S variant (also known as c.293C>G), located in coding exon 3 of the FKTN gene, results from a C to G substitution at nucleotide position 293. The threonine at codon 98 is replaced by serine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.069

BayesDel_addAF

Benign

-0.27

BayesDel_noAF

Benign

-0.32

Cadd

Benign

6.3

Dann

Benign

0.17

DEOGEN2

Benign

0.069

T;T;.;.

Eigen

Benign

-1.3

Eigen_PC

Benign

-1.2

FATHMM_MKL

Benign

0.069

M_CAP

Benign

0.058

MetaRNN

Benign

0.038

T;T;T;T

MetaSVM

Benign

-0.74

MutationAssessor

Benign

0.76

N;N;N;N

MutationTaster

Benign

1.0

N;N;N

PrimateAI

Benign

0.26

Sift4G

Benign

0.73

T;T;T;T

Polyphen

0.0

B;B;.;.

Vest4

0.13

MutPred

0.22

Gain of disorder (P = 0.0273);Gain of disorder (P = 0.0273);Gain of disorder (P = 0.0273);Gain of disorder (P = 0.0273);

MVP

0.45

MPC

0.074

ClinPred

0.0058

GERP RS

3.5

Varity_R

0.034

gMVP

0.24

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over