rs119463991

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_001079802.2(FKTN):​c.346C>T​(p.Gln116*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000249 in 1,607,904 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. Q116Q) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

FKTN
NM_001079802.2 stop_gained

Scores

2
4
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 2.21

Publications

4 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: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 9-105601325-C-T is Pathogenic according to our data. Variant chr9-105601325-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 3206.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FKTNNM_001079802.2 linkc.346C>T p.Gln116* stop_gained Exon 5 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.346C>T p.Gln116* stop_gained Exon 5 of 11 5 NM_001079802.2 ENSP00000350687.6 O75072-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152148
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
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
GnomAD2 exomes
AF:
0.00
AC:
0
AN:
249418
AF XY:
0.00
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
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:
0.00000137
AC:
2
AN:
1455756
Hom.:
0
Cov.:
29
AF XY:
0.00000138
AC XY:
1
AN XY:
724536
show subpopulations
African (AFR)
AF:
0.0000599
AC:
2
AN:
33402
American (AMR)
AF:
0.00
AC:
0
AN:
44716
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26098
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39596
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86168
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50998
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1108770
Other (OTH)
AF:
0.00
AC:
0
AN:
60246
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.0000131
AC:
2
AN:
152148
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74324
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41438
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5200
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68006
Other (OTH)
AF:
0.00
AC:
0
AN:
2084
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000199
Hom.:
0
Bravo
AF:
0.00000378
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 4 Pathogenic:2
Nov 01, 2003
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Jul 11, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: FKTN c.346C>T (p.Gln116X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 249418 control chromosomes. c.346C>T has been reported in the literature in individuals affected with Walker-Warburg Syndrome or related disorders. These data indicate that the variant may be associated with disease. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Walker-Warburg congenital muscular dystrophy Pathogenic:2
Nov 06, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Gln116*) in the FKTN gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in FKTN are known to be pathogenic (PMID: 17044012, 17878207, 18752264). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individuals with clinical features of muscular dystrophy-dystroglycanopathy (PMID: 14627679, 25814170). ClinVar contains an entry for this variant (Variation ID: 3206). For these reasons, this variant has been classified as Pathogenic. -

Jul 15, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Dilated cardiomyopathy 1X Pathogenic:1
Mar 12, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Pathogenic:1
Apr 04, 2025
Ambry Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Q116* pathogenic mutation (also known as c.346C>T), located in coding exon 3 of the FKTN gene, results from a C to T substitution at nucleotide position 346. This changes the amino acid from a glutamine to a stop codon within coding exon 3. This variant has been identified in the homozygous state and/or in conjunction with other FKTN variant(s) in individual(s) with features consistent with FKTN-related dystroglycanopathies (de Bernab&eacute; DB et al. J Med Genet, 2003 Nov;40:845-8; Lim BC et al. Neuromuscul Disord, 2010 Aug;20:524-30; Yang H et al. Brain Dev, 2015 Oct;37:880-6). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.61
D
BayesDel_noAF
Pathogenic
0.63
CADD
Pathogenic
35
DANN
Uncertain
1.0
Eigen
Uncertain
0.60
Eigen_PC
Uncertain
0.44
FATHMM_MKL
Uncertain
0.95
D
PhyloP100
2.2
Vest4
0.83
GERP RS
4.9
Mutation Taster
=2/198
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs119463991; hg19: chr9-108363606; API