rs746763506

Positions:

chr9-105604452-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_001079802.2(FKTN):c.607C>T(p.Arg203*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000235 in 1,613,882 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 (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000025 ( 0 hom. )

Consequence

FKTN
NM_001079802.2 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 3.01

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:

FKTN (HGNC:):

FKTN links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 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 9-105604452-C-T is Pathogenic according to our data. Variant chr9-105604452-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 225359.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr9-105604452-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FKTN	NM_001079802.2 linkuse as main transcript	c.607C>T	p.Arg203*	stop_gained	6/11	ENST00000357998.10	NP_001073270.1	O75072-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FKTN	ENST00000357998.10 linkuse as main transcript	c.607C>T	p.Arg203*	stop_gained	6/11	5	NM_001079802.2	ENSP00000350687.6		O75072-1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152090

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:

0.00

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

GnomAD3 exomes

AF:

0.00000797

AC:

AN:

250870

Hom.:

AF XY:

0.00000737

AC XY:

AN XY:

135600

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000579

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:

0.0000253

AC:

AN:

1461792

Hom.:

Cov.:

AF XY:

0.0000206

AC XY:

AN XY:

727210

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000894

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000279

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152090

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74274

show subpopulations

Gnomad4 AFR

AF:

0.00

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000151

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Dilated cardiomyopathy 1X

Pathogenic:2

Pathogenic, no assertion criteria provided	clinical testing	KTest Genetics, KTest	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 28, 2024	- -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 4

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	May 06, 2016	Variant summary: The FKTN variant, c.607C>T (p.Arg203X) causes a nonsense mutation in exon 5 resulting in a premature termination codon, a known mechanism for disease, as these types of variants are predicted to cause transcript degradation through nonsense mediated decay or produce a truncated protein. The varinat of interest was observed in the large, broad control population, ExAC, with an allele frequency of 1/121290, which does not exceed the estimated maximum expected allele frequency for a pathogenic FKTN variant of 1/200 for Fukuyama Congenital Muscular Dystrophy. The variant of interest has been reported in multiple affected individuals dx with Fukuyama Congenital Muscular Dystrophy (patient was homozygous for variant) and Muscular dystrophy-dystroglycanopathy(limb-girdle) via publications. One reputable database cites the variant as disease-causing. Therefore, taking all available lines of evidence into consideration, the variant of interest is classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Mar 21, 2017	- -

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

Pathogenic:1

Pathogenic, criteria provided, single submitter

reference population

Soonchunhyang University Bucheon Hospital, Soonchunhyang University Medical Center

Mar 18, 2016

- -

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

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Apr 01, 2022

- -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Feb 09, 2024

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 20961758, 25525159, 26809617, 28688748, 14627679, 34011823, 11165248) -

Walker-Warburg congenital muscular dystrophy

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 06, 2023

This sequence change creates a premature translational stop signal (p.Arg203*) 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 present in population databases (rs746763506, gnomAD 0.009%). This premature translational stop signal has been observed in individual(s) with FKTN-related disease (PMID: 11165248, 20961758, 26809617). ClinVar contains an entry for this variant (Variation ID: 225359). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.45

BayesDel_noAF

Pathogenic

0.60

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Uncertain

0.51

Eigen_PC

Uncertain

0.38

FATHMM_MKL

Uncertain

0.84

Vest4

0.84

GERP RS

4.5

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

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