NM_024301.5:c.328C>T

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 5P and 1B. PM2PM5PP5BP4

The NM_024301.5(FKRP):c.328C>T(p.Arg110Trp) variant causes a missense change. The variant allele was found at a frequency of 0.000015 in 1,528,916 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R110P) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000013 ( 0 hom. )

Consequence

FKRP
NM_024301.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:6

Conservation

PhyloP100: 4.95

Variant links:

Genes affected

FKRP (HGNC:17997): (fukutin related protein) This gene encodes a protein which is targeted to the medial Golgi apparatus and is necessary for posttranslational modification of dystroglycan. Mutations in this gene have been associated with congenital muscular dystrophy, cognitive disability, and cerebellar cysts. Several alternatively spliced transcript variants of this gene have been described, but the full-length nature of some of these variants has not been determined. [provided by RefSeq, Oct 2008]

FKRP links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr19-46755779-G-C is described in Lovd as [Pathogenic].

PP5

Variant 19-46755778-C-T is Pathogenic according to our data. Variant chr19-46755778-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 408718.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=5, Pathogenic=1}. Variant chr19-46755778-C-T is described in Lovd as [Pathogenic].

BP4

Computational evidence support a benign effect (MetaRNN=0.067923665). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FKRP	NM_024301.5 link	c.328C>T	p.Arg110Trp	missense_variant	Exon 4 of 4	ENST00000318584.10	NP_077277.1	Q9H9S5A0A024R0R7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FKRP	ENST00000318584.10 link	c.328C>T	p.Arg110Trp	missense_variant	Exon 4 of 4	1	NM_024301.5	ENSP00000326570.4		Q9H9S5

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152136

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000967

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000104

AC:

AN:

134338

Hom.:

AF XY:

0.000122

AC XY:

AN XY:

73588

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.000138

Gnomad EAS exome

AF:

0.00108

Gnomad SAS exome

AF:

0.0000460

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000131

AC:

AN:

1376664

Hom.:

Cov.:

AF XY:

0.0000133

AC XY:

AN XY:

677866

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000276

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000393

Gnomad4 SAS exome

AF:

0.0000127

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000349

GnomAD4 genome

AF:

0.0000328

AC:

AN:

152252

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74430

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000970

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000529

ExAC

AF:

0.0000555

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:4Uncertain:6

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:3

Jan 11, 2023

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 01, 2020

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 21296577, 18036232, 25135358) -

Aug 02, 2022

Athena Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy

Pathogenic:1

Dec 13, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: FKRP c.328C>T (p.Arg110Trp) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.0001 in 134338 control chromosomes, predominantly at a frequency of 0.0011 within the East Asian subpopulation in the gnomAD database. This frequency is not significantly higher than estimated for a pathogenic variant in FKRP causing Limb-Girdle Muscular Dystrophy, Autosomal Recessive (0.0001 vs 0.0024), allowing no conclusion about variant significance. c.328C>T has been reported in the literature in individuals affected with Limb-Girdle Muscular Dystrophy, Autosomal Recessive (Kang_2007,Song_2021). These data indicate that the variant may be associated with disease. A different variant affecting the same codon has been classified as pathogenic by our lab (c.329G>C, p.Arg110Pro), supporting the critical relevance of codon 110 to FKRP protein function. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 18036232, 33200426, internal data). ClinVar contains an entry for this variant (Variation ID: 408718). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Pathogenic:1

Jun 24, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A5

Pathogenic:1

Mar 19, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Walker-Warburg congenital muscular dystrophy

Pathogenic:1

Jan 11, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 110 of the FKRP protein (p.Arg110Trp). This variant is present in population databases (rs758759348, gnomAD 0.1%). This missense change has been observed in individuals with clinical features of limb-girdle muscular dystrophy (PMID: 18036232, 25135358, 33200426; internal data). ClinVar contains an entry for this variant (Variation ID: 408718). 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) has been performed 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. This variant disrupts the p.Arg110 amino acid residue in FKRP. Other variant(s) that disrupt this residue have been observed in individuals with FKRP-related conditions (PMID: 16368217), which suggests that this may be a clinically significant amino acid residue. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Autosomal recessive limb-girdle muscular dystrophy type 2I

Uncertain:1

Sep 16, 2020

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

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

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype

Uncertain:1

Mar 30, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R110W variant (also known as c.328C>T), located in coding exon 1 of the FKRP gene, results from a C to T substitution at nucleotide position 328. The arginine at codon 110 is replaced by tryptophan, an amino acid with dissimilar properties. This variant co-occurred with other FKRP variants in individuals reported to have limb-girdle muscular dystrophy phenotype; however, phase determination was not always clear and/or clinical details were limited (Kang PB et al. BMC Musculoskelet Disord, 2007 Nov;8:115; Song D et al. Clin Genet. 2021 Mar;99(3):384-395; Jensen SM et al. Neuromuscul Disord. 2023 Feb;33(2):119-132). This amino acid position is not 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.30

BayesDel_addAF

Benign

-0.10

BayesDel_noAF

Uncertain

0.030

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.70

.;D;D;.;T

Eigen

Benign

0.13

Eigen_PC

Benign

0.16

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.87

D;.;D;D;D

M_CAP

Pathogenic

0.83

MetaRNN

Benign

0.068

T;T;T;T;T

MetaSVM

Pathogenic

1.0

MutationAssessor

Benign

0.90

.;L;L;.;.

PrimateAI

Uncertain

0.72

PROVEAN

Uncertain

-2.9

.;D;D;.;.

REVEL

Uncertain

0.63

Sift

Uncertain

0.013

.;D;D;.;.

Sift4G

Uncertain

0.0070

D;D;D;D;D

Polyphen

0.99

.;D;D;.;.

Vest4

0.20, 0.22

MutPred

0.30

Loss of disorder (P = 0.001);Loss of disorder (P = 0.001);Loss of disorder (P = 0.001);Loss of disorder (P = 0.001);Loss of disorder (P = 0.001);

MVP

0.95

MPC

1.0

ClinPred

0.19

GERP RS

3.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.51

gMVP

0.73

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over