rs755092516

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBP6

The NM_001079802.2(FKTN):​c.869A>T​(p.Lys290Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000508 in 1,613,936 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000051 ( 0 hom. )

Consequence

FKTN
NM_001079802.2 missense

Scores

9
10

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:4

Conservation

PhyloP100: 0.812

Publications

0 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.03138444).
BP6
Variant 9-105615366-A-T is Benign according to our data. Variant chr9-105615366-A-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 265152.We mark this variant Likely_benign, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FKTNNM_001079802.2 linkc.869A>T p.Lys290Ile missense_variant Exon 8 of 11 ENST00000357998.10 NP_001073270.1 O75072-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FKTNENST00000357998.10 linkc.869A>T p.Lys290Ile missense_variant Exon 8 of 11 5 NM_001079802.2 ENSP00000350687.6 O75072-1

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152186
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000524
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
GnomAD2 exomes
AF:
0.000258
AC:
65
AN:
251468
AF XY:
0.000206
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00188
Gnomad ASJ exome
AF:
0.00
Gnomad EAS 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:
0.0000506
AC:
74
AN:
1461750
Hom.:
0
Cov.:
31
AF XY:
0.0000440
AC XY:
32
AN XY:
727196
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00165
AC:
74
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111892
Other (OTH)
AF:
0.00
AC:
0
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.501
Heterozygous variant carriers
0
7
13
20
26
33
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000526
AC:
8
AN:
152186
Hom.:
0
Cov.:
32
AF XY:
0.0000403
AC XY:
3
AN XY:
74370
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41448
American (AMR)
AF:
0.000524
AC:
8
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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.:
0
Bravo
AF:
0.000125
ExAC
AF:
0.000165
AC:
20

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2
Jun 12, 2017
Stanford Center for Inherited Cardiovascular Disease, Stanford University
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:provider interpretation

p.Lys290Ile (c.869A>T) in the FKTN gene (NM_001079802.1) GeneDx classifies this variant as a variant of uncertain significance. Given its prevalence in the general population we consider this variant a variant of uncertain significance, likely benign and we do not feel it is suitable for assessing risk in healthy relatives ("predictive genetic testing"). In addition, two pathogenic variants in the FKTN gene must be present for an individual to manifest symptoms. The FKTN gene encodes the fukutin protein, in which two loss of function variants (autosomal recessive inheritance) causes a severe muscular dystrophy. Autosomal recessive inheritance of both loss-of-function and pathogenic missense variants can cause a severe dilated cardiomyopathy that tends to onset in childhood. In a paper by Arimura et al (2009), 1 out of 172 DCM patients was a compound heterozygote for a deletion and missense variant (p.Cys101Phe in the FKTN gene. This was a 19 year old Japanese patient with a high CK and symptoms of DCM, accompanied by a reduced ejection fraction. Two other DCM patients and 3 controls were heterozygous for the insertion allele demonstrating that a single pathogenic variant is not enough to cause severe disease. Murakami et al (2006) identified compound heterozygous pathogenic variants in 6 individuals from 4 families with dilated cardiomyopathy and no signs of muscular dystrophy: one patient died at 12 years old and another required transplant at 18. There is no published literature to indicate that this variant is associated with cardiomyopathy. There is no published literature showing that a single variant predisposes an individual to cardiovascular disease. This variant is present in ClinVar. It has been submitted by two labs: GeneDx and Invitae, both of which classify this variant as a variant of uncertain significnace. Invitae saw this variant in a patient with Walker-Warburg congential muscular dystrophy. Per the test report, "in silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function". The lysine at codon 290 is not conserved across species, nor are neighboring amino acids. There are few variants at nearby codons listed in ClinVar. The variant was reported online in 68 of 138,611 individuals in the Genome Aggregation Consortium Dataset (gnomAD; http://gnomad.broadinstitute.org/), which currently includes variant calls on >140,000 unrelated individuals of African, Asian, European, Ashkenazi, Latino descent. Specifically, the variant was observed in 67 of 17,210 individuals of Latino descent (MAF=0.2%) and 1 of 3,234 individuals of "other" descent. Another variant at this codon, p.Lys290Glu is present in 1 out of 123,125 individuals. The phenotype of those individuals is not publicly available. The dataset is comprised of multiple cohorts, some of which were recruited from the general population, others were enriched for common cardiovascular disease. -

Oct 28, 2019
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 27332903) -

not specified Uncertain:1
Mar 14, 2025
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.869A>T (p.Lys290Ile) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00026 in 251468 control chromosomes, predominantly at a frequency of 0.0019 within the Latino subpopulation in the gnomAD database. This frequency is not significantly higher than estimated for a pathogenic variant in FKTN causing Dilated Cardiomyopathy (0.00026 vs 0.004), allowing no conclusion about variant significance. c.869A>T has been reported in the literature in at least one case of sudden cardiac death without evidence for causailty (e.g. Bagnall_2016). These report(s) do not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 27332903). ClinVar contains an entry for this variant (Variation ID: 265152). Based on the evidence outlined above, the variant was classified as uncertain significance. -

FKTN-related disorder Benign:1
Apr 17, 2023
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Hypertrophic cardiomyopathy Benign:1
Feb 05, 2019
Center for Advanced Laboratory Medicine, UC San Diego Health, University of California San Diego
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Jan 24, 2024
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Walker-Warburg congenital muscular dystrophy Benign:1
Jan 15, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.14
BayesDel_addAF
Benign
-0.17
T
BayesDel_noAF
Uncertain
-0.030
CADD
Benign
18
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.64
D;D;.;.
Eigen
Benign
-0.46
Eigen_PC
Benign
-0.41
FATHMM_MKL
Benign
0.093
N
LIST_S2
Uncertain
0.89
.;D;.;D
M_CAP
Uncertain
0.12
D
MetaRNN
Benign
0.031
T;T;T;T
MetaSVM
Uncertain
-0.0016
T
MutationAssessor
Uncertain
2.8
M;M;M;M
PhyloP100
0.81
PrimateAI
Benign
0.30
T
PROVEAN
Uncertain
-2.9
.;D;.;D
REVEL
Uncertain
0.30
Sift
Benign
0.10
.;T;.;T
Sift4G
Benign
0.17
T;T;T;T
Polyphen
0.017
B;B;.;.
Vest4
0.41
MutPred
0.40
Loss of ubiquitination at K290 (P = 0.0255);Loss of ubiquitination at K290 (P = 0.0255);Loss of ubiquitination at K290 (P = 0.0255);Loss of ubiquitination at K290 (P = 0.0255);
MVP
0.81
MPC
0.20
ClinPred
0.11
T
GERP RS
3.8
Varity_R
0.21
gMVP
0.58
Mutation Taster
=90/10
polymorphism

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

Other links and lift over

dbSNP: rs755092516; hg19: chr9-108377647; API