rs533603648

chr9-105575124-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001079802.2(FKTN):c.92A>G(p.Tyr31Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000127 in 1,579,192 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. Y31Y) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000013 (0 hom.)
• Consequence: FKTN NM_001079802.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 6.20

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FKTN	NM_001079802.2	c.92A>G	p.Tyr31Cys	missense_variant	3/11	ENST00000357998.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FKTN	ENST00000357998.10	c.92A>G	p.Tyr31Cys	missense_variant	3/11	5	NM_001079802.2	P1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152182 Hom.: 0 Cov.: 32

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

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251258 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135802

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: 0.0000126 AC: 18 AN: 1426892 Hom.: 0 Cov.: 25 AF XY: 0.0000126 AC XY: 9 AN XY: 712160

Gnomad4 AFR exome AF: 0.0000305

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: 0.0000148

Gnomad4 OTH exome AF: 0.0000169

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152300 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74472

Gnomad4 AFR AF: 0.0000481

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: 0.0000282 Hom.: 0

Bravo AF: 0.00000756

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Walker-Warburg congenital muscular dystrophy Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Mar 18, 2022	This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 31 of the FKTN protein (p.Tyr31Cys). This variant is present in population databases (rs533603648, 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: 568936). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -
Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Apr 01, 2020	- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Revvity Omics, Revvity

Jun 01, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Pathogenic	0.31
Cadd	Pathogenic	27
Dann	Uncertain	1.0
DEOGEN2	Benign	0.37	T;T;.;.
Eigen	Uncertain	0.67
Eigen_PC	Uncertain	0.65
FATHMM_MKL	Uncertain	0.92	D
M_CAP	Uncertain	0.26	D
MetaRNN	Uncertain	0.74	D;D;D;D
MetaSVM	Uncertain	0.77	D
MutationAssessor	Uncertain	2.2	M;M;M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.64	T
Sift4G	Uncertain	0.044	D;D;D;D
Polyphen		1.0	D;D;.;.
Vest4		0.92
MutPred		0.37		Loss of ubiquitination at K29 (P = 0.0714);Loss of ubiquitination at K29 (P = 0.0714);Loss of ubiquitination at K29 (P = 0.0714);Loss of ubiquitination at K29 (P = 0.0714);
MVP		0.93
MPC		0.48
ClinPred		0.94	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.15
gMVP		0.76

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

LitVar

Other links and lift over

dbSNP: rs533603648; hg19: chr9-108337405;