chr9-105575066-C-G

Variant names:

• chr9-105575066-C-G
• rs939985733
• NM_001079802.2:c.34C>G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_001079802.2(FKTN):​c.34C>G​(p.Leu12Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,168 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: FKTN NM_001079802.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 1.46

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.

• PM1: In a region_of_interest Required and sufficient for interaction with POMGNT1 (size 21) in uniprot entity FKTN_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_001079802.2
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.16611868).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FKTN	NM_001079802.2	c.34C>G	p.Leu12Val	missense_variant	Exon 3 of 11	ENST00000357998.10	NP_001073270.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FKTN	ENST00000357998.10	c.34C>G	p.Leu12Val	missense_variant	Exon 3 of 11	5	NM_001079802.2	ENSP00000350687.6

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152168 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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

GnomAD4 exome Cov.: 28

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152168 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74330

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000655

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

Bravo AF: 0.0000378

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

Jun 21, 2021

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Feb 03, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 12 of the FKTN protein (p.Leu12Val). This variant is not present in population databases (gnomAD no frequency). 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: 528829). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

not provided Uncertain:1

Mar 15, 2024

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

BP4 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.066
BayesDel_addAF	Uncertain	0.039	T
BayesDel_noAF	Benign	-0.18
CADD	Benign	16
DANN	Benign	0.91
DEOGEN2	Benign	0.16	T;T;.;.
Eigen	Benign	-0.39
Eigen_PC	Benign	-0.18
FATHMM_MKL	Benign	0.67	D
LIST_S2	Benign	0.80	.;T;.;T
M_CAP	Benign	0.043	D
MetaRNN	Benign	0.17	T;T;T;T
MetaSVM	Uncertain	-0.16	T
MutationAssessor	Benign	1.4	L;L;L;L
PrimateAI	Benign	0.42	T
PROVEAN	Benign	-0.62	.;N;N;N
REVEL	Benign	0.21
Sift	Benign	0.24	.;T;T;T
Sift4G	Benign	0.61	T;T;T;T
Polyphen		0.0010	B;B;.;.
Vest4		0.27
MutPred		0.25		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		0.77
MPC		0.083
ClinPred		0.43	T
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.17
gMVP		0.59

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: rs939985733; hg19: chr9-108337347;