rs146049441

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_001079802.2(FKTN):c.383G>A(p.Arg128Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00022 in 1,612,256 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/21 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. R128W) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00023 ( 1 hom. )

Consequence

FKTN
NM_001079802.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:9

Conservation

PhyloP100: -0.102

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 Uncertain_significance. Variant got 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.068431556).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FKTN	NM_001079802.2 link	c.383G>A	p.Arg128Gln	missense_variant	Exon 6 of 11	ENST00000357998.10	NP_001073270.1	O75072-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FKTN	ENST00000357998.10 link	c.383G>A	p.Arg128Gln	missense_variant	Exon 6 of 11	5	NM_001079802.2	ENSP00000350687.6		O75072-1

Frequencies

GnomAD3 genomes

AF:

0.000131

AC:

AN:

152142

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.000279

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000561

AC:

AN:

249702

Hom.:

AF XY:

0.0000444

AC XY:

AN XY:

135146

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000893

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000229

AC:

335

AN:

1460114

Hom.:

Cov.:

AF XY:

0.000202

AC XY:

147

AN XY:

726380

show subpopulations

Gnomad4 AFR exome

AF:

0.0000897

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000101

Gnomad4 SAS exome

AF:

0.0000580

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000286

Gnomad4 OTH exome

AF:

0.0000830

GnomAD4 genome

AF:

0.000131

AC:

AN:

152142

Hom.:

Cov.:

AF XY:

0.0000942

AC XY:

AN XY:

74328

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000279

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000232

Hom.:

Bravo

AF:

0.000140

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000330

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.000178

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:9

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:5

Apr 11, 2024

Athena Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Available data are insufficient to determine the clinical significance of the variant at this time. The frequency of this variant in the general population is uninformative in assessment of its pathogenicity. (http://gnomad.broadinstitute.org) Polyphen and MutationTaster yielded discordant predictions regarding whether this amino acid change is damaging to the protein. -

Sep 10, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 30564623) -

Feb 07, 2023

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 15, 2023

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 17, 2017

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Walker-Warburg congenital muscular dystrophy

Uncertain:2

Jan 24, 2020

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Oct 05, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 128 of the FKTN protein (p.Arg128Gln). This variant is present in population databases (rs146049441, gnomAD 0.01%). 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: 286471). 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) performed at Invitae indicates that this missense variant is not expected to disrupt FKTN 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. -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 4;C1969024:Dilated cardiomyopathy 1X;C1969040:Autosomal recessive limb-girdle muscular dystrophy type 2M;C2751052:Muscular dystrophy-dystroglycanopathy (congenital without intellectual disability), type B4;C4284790:Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A1

Uncertain:1

Jul 05, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype

Uncertain:1

Jul 27, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R128Q variant (also known as c.383G>A), located in coding exon 4 of the FKTN gene, results from a G to A substitution at nucleotide position 383. The arginine at codon 128 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species, and glutamine is the reference amino acid in other 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

0.061

BayesDel_addAF

Benign

-0.21

BayesDel_noAF

Benign

-0.33

CADD

Benign

7.8

DANN

Benign

0.47

DEOGEN2

Benign

0.096

T;T;.;.

Eigen

Benign

-1.0

Eigen_PC

Benign

-0.87

FATHMM_MKL

Benign

0.52

LIST_S2

Benign

0.78

.;T;.;T

M_CAP

Benign

0.018

MetaRNN

Benign

0.068

T;T;T;T

MetaSVM

Benign

-0.72

MutationAssessor

Benign

-1.1

N;N;N;N

PrimateAI

Benign

0.21

PROVEAN

Benign

-0.16

.;N;N;N

REVEL

Uncertain

0.30

Sift

Benign

0.73

.;T;T;T

Sift4G

Benign

0.75

T;T;T;T

Polyphen

0.0

B;B;.;.

Vest4

0.26

MVP

0.45

MPC

0.094

ClinPred

0.016

GERP RS

-1.4

Varity_R

0.014

gMVP

0.40

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