rs769568971
Variant summary
Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2PM5BP4
The NM_024301.5(FKRP):c.1270A>C(p.Asn424His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000434 in 1,611,674 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. N424?) has been classified as Pathogenic.
Frequency
Consequence
NM_024301.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 3 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
FKRP | NM_024301.5 | c.1270A>C | p.Asn424His | missense_variant | Exon 4 of 4 | ENST00000318584.10 | NP_077277.1 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
FKRP | ENST00000318584.10 | c.1270A>C | p.Asn424His | missense_variant | Exon 4 of 4 | 1 | NM_024301.5 | ENSP00000326570.4 | ||
FKRP | ENST00000391909.7 | c.1270A>C | p.Asn424His | missense_variant | Exon 4 of 4 | 2 | ENSP00000375776.2 | |||
FKRP | ENST00000597339.5 | n.247-5113A>C | intron_variant | Intron 3 of 3 | 5 | |||||
FKRP | ENST00000600646.5 | n.247+8055A>C | intron_variant | Intron 3 of 3 | 3 |
Frequencies
GnomAD3 genomes AF: 0.0000591 AC: 9AN: 152212Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.0000327 AC: 8AN: 244516Hom.: 0 AF XY: 0.0000378 AC XY: 5AN XY: 132446
GnomAD4 exome AF: 0.0000418 AC: 61AN: 1459462Hom.: 0 Cov.: 32 AF XY: 0.0000400 AC XY: 29AN XY: 725820
GnomAD4 genome AF: 0.0000591 AC: 9AN: 152212Hom.: 0 Cov.: 33 AF XY: 0.0000538 AC XY: 4AN XY: 74370
ClinVar
Submissions by phenotype
not provided Uncertain:4
FKRP: PM2 -
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A variant of uncertain significance has been identified in the FKRP gene. The N424H variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The N424H variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016). The N424H variant is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties. In silico analysis predicts this variant is probably damaging to the protein structure/function. However, this substitution occurs at a position that is not conserved. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -
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Autosomal recessive limb-girdle muscular dystrophy type 2I;C1847759:Muscular dystrophy-dystroglycanopathy type B5;C3150413:Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A5;C4284790:Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A1 Uncertain:1
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Autosomal recessive limb-girdle muscular dystrophy type 2I Uncertain:1
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Muscular dystrophy-dystroglycanopathy type B5 Uncertain:1
This variant was classified as: Uncertain significance. The available evidence favors the pathogenic nature of this variant, however the currently available data is insufficient to conclusively support its pathogenic nature. Thus this variant is classified as Uncertain significance - favor pathogenic. The following ACMG criteria were applied in classifying this variant: PM2,PP3. -
Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A5 Uncertain:1
Based on the classification scheme VCGS_Germline_v1.3.3, this variant is classified as 3B-VUS. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with muscular dystrophy-dystroglycanopathy (OMIM). 0106 - This gene is associated with autosomal recessive disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from asparagine to histidine (exon 4). (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD v3 <0.01 for a recessive condition (7 heterozygotes, 0 homozygotes). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v3) (2 heterozygotes, 0 homozygotes). (I) 0502 - Missense variant with conflicting in silico predictions and uninformative conservation. (I) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0809 - Previous evidence of pathogenicity for this variant is inconclusive. The variant has been classified as a Variant of Uncertain Significance (ClinVar). (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1206 - This variant has been shown to be paternally inherited (by trio analysis). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Cardiovascular phenotype Uncertain:1
The p.N424H variant (also known as c.1270A>C), located in coding exon 1 of the FKRP gene, results from an A to C substitution at nucleotide position 1270. The asparagine at codon 424 is replaced by histidine, an amino acid with similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Walker-Warburg congenital muscular dystrophy Uncertain:1
This sequence change replaces asparagine, which is neutral and polar, with histidine, which is basic and polar, at codon 424 of the FKRP protein (p.Asn424His). This variant is present in population databases (rs769568971, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with FKRP-related conditions. ClinVar contains an entry for this variant (Variation ID: 449685). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on FKRP 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at