rs119463992
Variant summary
Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong
The NM_001079802.2(FKTN):c.920G>A(p.Arg307Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000101 in 1,584,518 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_001079802.2 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 14 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000132 AC: 2AN: 151836Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000120 AC: 3AN: 249118Hom.: 0 AF XY: 0.0000148 AC XY: 2AN XY: 134878
GnomAD4 exome AF: 0.00000977 AC: 14AN: 1432682Hom.: 0 Cov.: 26 AF XY: 0.0000140 AC XY: 10AN XY: 714716
GnomAD4 genome AF: 0.0000132 AC: 2AN: 151836Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74152
ClinVar
Submissions by phenotype
not provided Pathogenic:2
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Has been reported in individuals with a dystroglycinopathy phenotype (Godfrey et al., 2006; Godfrey, et al., 2007; Vuillaumier-Barrot et al., 2009; Johnson et al., 2018); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Functional studies in CHO cells showed that this variant does not affect FKTN expression or localization (Godfrey et al., 2006); This variant is associated with the following publications: (PMID: 31589614, 17044012, 25821721, 32528171, 20961758, 19299310, 24144914, 19833706, 26923585, 19266496, 19396839, 32906206, 30060766, 17878207, 19179078, 30564623) -
Muscular dystrophy-dystroglycanopathy (congenital without intellectual disability), type B4 Pathogenic:1
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Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 4;C1969024:Dilated cardiomyopathy 1X;C1969040:Autosomal recessive limb-girdle muscular dystrophy type 2M;C2751052:Muscular dystrophy-dystroglycanopathy (congenital without intellectual disability), type B4 Pathogenic:1
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Dilated cardiomyopathy 1X Pathogenic:1
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Autosomal recessive limb-girdle muscular dystrophy type 2M Pathogenic:1
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Cardiovascular phenotype Pathogenic:1
The p.R307Q pathogenic mutation (also known as c.920G>A), located in coding exon 7 of the FKTN gene, results from a G to A substitution at nucleotide position 920. The arginine at codon 307 is replaced by glutamine, an amino acid with highly similar properties. This variant has been identified in the homozygous state and/or in conjunction with other FKTN variant(s) in individual(s) with features consistent with FKTN-related dystroglycanopathies, most often presenting as limb-girdle muscular dystrophy-like phenotype; in at least one instance, the variants were identified in trans (Godfrey C et al. Ann Neurol, 2006 Nov;60:603-610; Godfrey C et al. Brain, 2007 Oct;130:2725-35; Mercuri E et al. Neurology, 2009 May;72:1802-9; Vuillaumier-Barrot S et al. Neuromuscul Disord, 2009 Mar;19:182-8; Carlson CR et al. Neurology, 2017 Dec;89:2374-2380; Johnson K et al. Skelet Muscle, 2018 Jul;8:23; Erbe LS et al. Int J Mol Sci, 2023 Sep;24). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this variant is interpreted as a disease-causing mutation. -
Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 4 Pathogenic:1
Variant summary: FKTN c.920G>A (p.Arg307Gln) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 249118 control chromosomes (gnomAD). c.920G>A has been reported in the literature in multiple affected individuals (Ceyhan-Birsoy_2015, Godfrey_2007, Johnson_2018, Yis_2011). These data indicate that the variant is very likely to be associated with disease. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Walker-Warburg congenital muscular dystrophy Pathogenic:1
This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 307 of the FKTN protein (p.Arg307Gln). This variant is present in population databases (rs119463992, gnomAD 0.01%). This missense change has been observed in individual(s) with FKTN-related conditions (PMID: 17044012, 19179078, 19396839, 25821721, 30060766). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 3208). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt FKTN protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects FKTN function (PMID: 26923585). For these reasons, this variant has been classified as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at