chr9-105635176-C-T

Variant names:

Variant summary

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

The NM_001079802.2(FKTN):c.1298C>T(p.Thr433Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000161 in 1,614,110 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/22 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. T433A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000016 ( 1 hom. )

Consequence

FKTN
NM_001079802.2 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.618

Publications

2 publications found

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 Gene-Disease associations (from GenCC):

autosomal recessive limb-girdle muscular dystrophy type 2M
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P
muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 4
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet, G2P
myopathy caused by variation in FKTN
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
familial isolated dilated cardiomyopathy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
congenital muscular dystrophy without intellectual disability
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
muscle-eye-brain disease
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
muscular dystrophy-dystroglycanopathy, type A
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
dilated cardiomyopathy 1X
Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics

FKTN links:

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=0.12656614).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FKTN	NM_001079802.2 link	c.1298C>T	p.Thr433Met	missense_variant	Exon 11 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.1298C>T	p.Thr433Met	missense_variant	Exon 11 of 11	5	NM_001079802.2	ENSP00000350687.6		O75072-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152126

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000192

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000318

AC:

AN:

251426

AF XY:

0.0000368

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000109

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000164

AC:

AN:

1461866

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

727232

show subpopulations

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:

0.0000252

AC:

AN:

39698

South Asian (SAS)

AF:

0.000243

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:

0.00000180

AC:

AN:

1111988

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.477

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000131

AC:

AN:

152244

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74448

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41542

American (AMR)

AF:

0.00

AC:

AN:

15292

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.000193

AC:

AN:

5184

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10604

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68006

Other (OTH)

AF:

0.00

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.00

Hom.:

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Walker-Warburg congenital muscular dystrophy

Uncertain:2

Oct 28, 2019

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jul 06, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 433 of the FKTN protein (p.Thr433Met). This variant is present in population databases (rs201590151, gnomAD 0.02%). 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: 570951). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The methionine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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. -

not specified

Uncertain:1

Apr 27, 2023

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: FKTN c.1298C>T (p.Thr433Met) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 3.2e-05 in 251426 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1298C>T has been reported in the literature in an individual affected with Cardiomyopathy without strong evidence for causality (example: Mazzarotto_2020). This report does not provide unequivocal conclusions about association of the variant with Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 31983221). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.077

BayesDel_addAF

Benign

-0.43

BayesDel_noAF

Benign

-0.60

CADD

Benign

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.30

T;T

Eigen

Benign

-0.47

Eigen_PC

Benign

-0.57

FATHMM_MKL

Benign

0.15

LIST_S2

Benign

0.63

.;T

M_CAP

Benign

0.030

MetaRNN

Benign

0.13

T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

1.8

L;L

PhyloP100

0.62

PrimateAI

Benign

0.32

PROVEAN

Benign

-1.7

.;N

REVEL

Benign

0.11

Sift

Benign

0.046

.;D

Sift4G

Uncertain

0.042

D;D

Polyphen

0.98

D;D

Vest4

0.069

MVP

0.35

MPC

0.088

ClinPred

0.13

GERP RS

2.3

Varity_R

0.025

gMVP

0.41

Mutation Taster

=88/12

polymorphism

(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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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over