9-105607919-T-G

Variant names:

• chr9-105607919-T-G
• rs398123558
• NM_001079802.2:c.748T>G

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PM5 PP3

The NM_001079802.2(FKTN):​c.748T>G​(p.Cys250Gly) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,459,612 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C250R) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: FKTN NM_001079802.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.48
• 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 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-105607919-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 93524.
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

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.748T>G	p.Cys250Gly	missense	Exon 7 of 11	NP_001073270.1
	FKTN	NM_001351496.2		c.748T>G	p.Cys250Gly	missense	Exon 8 of 12	NP_001338425.1
	FKTN	NM_006731.2		c.748T>G	p.Cys250Gly	missense	Exon 6 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.748T>G	p.Cys250Gly	missense	Exon 7 of 11	ENSP00000350687.6
	FKTN	ENST00000223528.6	TSL:1	c.748T>G	p.Cys250Gly	missense	Exon 6 of 10	ENSP00000223528.2
	FKTN	ENST00000602526.1	TSL:1	n.*786T>G		non_coding_transcript_exon	Exon 7 of 11	ENSP00000473347.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459612 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 726340

African (AFR) AF: 0.00 AC: 0 AN: 33428

American (AMR) AF: 0.00 AC: 0 AN: 44700

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26110

East Asian (EAS) AF: 0.00 AC: 0 AN: 39624

South Asian (SAS) AF: 0.00 AC: 0 AN: 86218

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 9.01e-7 AC: 1 AN: 1110056

Other (OTH) AF: 0.00 AC: 0 AN: 60304

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	33
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.78	D
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.92	D
M_CAP	Pathogenic	0.75	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.5	M
PhyloP100		6.5
PrimateAI	Uncertain	0.65	T
PROVEAN	Pathogenic	-10	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.93		Gain of disorder (P = 0.0129)
MVP		0.93
MPC		0.51
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.96
gMVP		0.98
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.69		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.51		Position offset: 0
DS_DL_spliceai		0.69		Position offset: 32

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs398123558; hg19: chr9-108370200;