rs1554751104

Variant names:

• chr9-105601149-C-G
• rs1554751104
• NM_001079802.2:c.170C>G

Your query was ambiguous. Multiple possible variants found:

• chr9-105601149-C-G
• chr9-105601149-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 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. 14/22 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
• Publications: 0 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001079802.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FKTN	NM_001079802.2	MANE Select	c.170C>G	p.Ala57Gly	missense	Exon 5 of 11	NP_001073270.1
	FKTN	NM_001351496.2		c.170C>G	p.Ala57Gly	missense	Exon 6 of 12	NP_001338425.1
	FKTN	NM_006731.2		c.170C>G	p.Ala57Gly	missense	Exon 4 of 10	NP_006722.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FKTN	ENST00000357998.10	TSL:5 MANE Select	c.170C>G	p.Ala57Gly	missense	Exon 5 of 11	ENSP00000350687.6
	FKTN	ENST00000223528.6	TSL:1	c.170C>G	p.Ala57Gly	missense	Exon 4 of 10	ENSP00000223528.2
	FKTN	ENST00000602526.1	TSL:1	n.*90C>G		non_coding_transcript_exon	Exon 4 of 11	ENSP00000473347.1

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

African (AFR) AF: 0.00 AC: 0 AN: 32738

American (AMR) AF: 0.00 AC: 0 AN: 44450

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25788

East Asian (EAS) AF: 0.00 AC: 0 AN: 39430

South Asian (SAS) AF: 0.00 AC: 0 AN: 85066

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53008

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5426

European-Non Finnish (NFE) AF: 9.27e-7 AC: 1 AN: 1078484

Other (OTH) AF: 0.00 AC: 0 AN: 58962

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

Mar 26, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 v4.9

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
Eigen	Benign	-0.021
Eigen_PC	Benign	0.16
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.89	D
M_CAP	Benign	0.034	D
MetaRNN	Benign	0.31	T
MetaSVM	Uncertain	-0.21	T
MutationAssessor	Benign	1.6	L
PhyloP100		3.3
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-1.2	N
REVEL	Benign	0.27
Sift	Benign	0.30	T
Sift4G	Benign	0.42	T
Polyphen		0.0070	B
Vest4		0.32
MutPred		0.42		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
Mutation Taster		=78/22	polymorphism

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

Other links and lift over

dbSNP: rs1554751104; hg19: chr9-108363430;