NM_001079802.2:c.397A>C

Variant names:

• chr9-105604242-A-C
• NM_001079802.2:c.397A>C
• FKTN p.Met133Leu

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001079802.2(FKTN):​c.397A>C​(p.Met133Leu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 13/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M133V) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FKTN NM_001079802.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.67
• 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: G2P, Labcorp Genetics (formerly Invitae), Orphanet
• muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 4

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, 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 2 ACMG points.

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

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FKTN	NM_001079802.2	MANE Select	c.397A>C	p.Met133Leu	missense	Exon 6 of 11	NP_001073270.1	O75072-1
	FKTN	NM_001351496.2		c.397A>C	p.Met133Leu	missense	Exon 7 of 12	NP_001338425.1	O75072-1
	FKTN	NM_006731.2		c.397A>C	p.Met133Leu	missense	Exon 5 of 10	NP_006722.2	O75072-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FKTN	ENST00000357998.10	TSL:5 MANE Select	c.397A>C	p.Met133Leu	missense	Exon 6 of 11	ENSP00000350687.6	O75072-1
	FKTN	ENST00000223528.6	TSL:1	c.397A>C	p.Met133Leu	missense	Exon 5 of 10	ENSP00000223528.2	O75072-1
	FKTN	ENST00000602526.1	TSL:1	n.*435A>C		non_coding_transcript_exon	Exon 6 of 11	ENSP00000473347.1	R4GMU0

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Uncertain	0.098	D
BayesDel_noAF	Benign	-0.10
CADD	Benign	18
DANN	Benign	0.96
DEOGEN2	Benign	0.18	T
Eigen	Benign	-0.0065
Eigen_PC	Benign	0.13
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.84	T
M_CAP	Benign	0.052	D
MetaRNN	Uncertain	0.46	T
MetaSVM	Uncertain	0.16	D
MutationAssessor	Benign	2.0	M
PhyloP100		3.7
PrimateAI	Benign	0.48	T
PROVEAN	Benign	-0.94	N
REVEL	Uncertain	0.32
Sift	Benign	0.38	T
Sift4G	Benign	0.39	T
Varity_R		0.30
gMVP		0.62
Mutation Taster		=65/35	polymorphism

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr9-108366523;