rs539089647

chr9-105619935-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP3

The NM_001079802.2(FKTN):c.1046T>C(p.Val349Ala) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000807 in 1,611,374 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/2 splice prediction tools predict no significant impact on normal splicing. 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. V349I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

FKTN
NM_001079802.2 missense, splice_region

Scores

Splicing: ADA: 0.3852

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 7.12

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 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.81

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FKTN	NM_001079802.2 linkuse as main transcript	c.1046T>C	p.Val349Ala	missense_variant, splice_region_variant	10/11	ENST00000357998.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FKTN	ENST00000357998.10 linkuse as main transcript	c.1046T>C	p.Val349Ala	missense_variant, splice_region_variant	10/11	5	NM_001079802.2	P1	O75072-1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152206

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000965

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251144

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135764

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.00

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:

0.00000617

AC:

AN:

1459050

Hom.:

Cov.:

AF XY:

0.00000689

AC XY:

AN XY:

725998

show subpopulations

Gnomad4 AFR exome

AF:

0.000209

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:

0.00000180

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152324

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74492

show subpopulations

Gnomad4 AFR

AF:

0.0000962

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Aug 08, 2017

A variant of uncertain significance has been identified in the FKTN gene. The V349A variant has not been published as pathogenic or been reported as benign to our knowledge. This variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). This substitution occurs at a position that is conserved across species and in silico analysis predicts this variant is probably damaging to the protein structure/function. Nevertheless, V349A is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 02, 2018

The p.V349A variant (also known as c.1046T>C), located in coding exon 8 of the FKTN gene, results from a T to C substitution at nucleotide position 1046. The valine at codon 349 is replaced by alanine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Walker-Warburg congenital muscular dystrophy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 17, 2021

This sequence change replaces valine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 349 of the FKTN protein (p.Val349Ala). This variant is present in population databases (rs539089647, 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: 451226). 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 disruptive. 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

Benign

0.15

BayesDel_addAF

Uncertain

0.14

BayesDel_noAF

Pathogenic

0.21

Cadd

Pathogenic

Dann

Uncertain

1.0

DEOGEN2

Benign

0.41

T;T;.;.

Eigen

Pathogenic

0.83

Eigen_PC

Pathogenic

0.81

FATHMM_MKL

Pathogenic

0.98

M_CAP

Uncertain

0.11

MetaRNN

Pathogenic

0.81

D;D;D;D

MetaSVM

Uncertain

-0.28

MutationAssessor

Uncertain

2.6

M;M;M;M

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Uncertain

0.70

Sift4G

Benign

0.077

T;T;T;T

Polyphen

0.98

D;D;.;.

Vest4

0.83

MVP

0.93

MPC

0.39

ClinPred

0.91

GERP RS

5.9

Varity_R

0.21

gMVP

0.69

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.39

dbscSNV1_RF

Benign

0.59

SpliceAI score (max)

0.23

Details are displayed if max score is > 0.2

DS_AL_spliceai

0.23

Position offset: -1

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