rs1554751104

chr9-105601149-C-Gchr9-105601149-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_001079802.2(FKTN):c.170C>G(p.Ala57Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000703 in 1,423,352 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 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. A57S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: FKTN NM_001079802.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.32

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3084321).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FKTN	NM_001079802.2	c.170C>G	p.Ala57Gly	missense_variant	5/11	ENST00000357998.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FKTN	ENST00000357998.10	c.170C>G	p.Ala57Gly	missense_variant	5/11	5	NM_001079802.2	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 7.03e-7 AC: 1 AN: 1423352 Hom.: 0 Cov.: 26 AF XY: 0.00 AC XY: 0 AN XY: 710274

Gnomad4 AFR exome AF: 0.00

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: 9.27e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000468 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Walker-Warburg congenital muscular dystrophy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 26, 2022

Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. This variant has not been reported in the literature in individuals affected with FKTN-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 57 of the FKTN protein (p.Ala57Gly). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
BayesDel_addAF	Uncertain	0.074	D
BayesDel_noAF	Benign	-0.13
Cadd	Benign	22
Dann	Uncertain	0.99
DEOGEN2	Benign	0.22	T;T;.;.
Eigen	Benign	-0.021
Eigen_PC	Benign	0.16
FATHMM_MKL	Uncertain	0.94	D
M_CAP	Benign	0.034	D
MetaRNN	Benign	0.31	T;T;T;T
MetaSVM	Uncertain	-0.21	T
MutationAssessor	Benign	1.6	L;L;L;L
MutationTaster	Benign	0.96	D;D;D
PrimateAI	Benign	0.31	T
Sift4G	Benign	0.42	T;T;T;T
Polyphen		0.0070	B;B;.;.
Vest4		0.32
MutPred		0.42		Gain of sheet (P = 0.0028);Gain of sheet (P = 0.0028);Gain of sheet (P = 0.0028);Gain of sheet (P = 0.0028);
MVP		0.86
MPC		0.087
ClinPred		0.55	D
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.11
gMVP		0.56

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

Other links and lift over

dbSNP: rs1554751104; hg19: chr9-108363430;