19-46756004-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B. PM1PM2PP2BP4

The NM_024301.5(FKRP):​c.554C>T​(p.Ala185Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000193 in 1,556,938 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. A185G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 7.1e-7 ( 0 hom. )

Consequence

FKRP
NM_024301.5 missense

Scores

3
4
12

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 2.03

Publications

0 publications found
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 Gene-Disease associations (from GenCC):
  • autosomal recessive limb-girdle muscular dystrophy type 2I
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Orphanet, Labcorp Genetics (formerly Invitae), Ambry Genetics
  • muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A5
    Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Genomics England PanelApp, G2P, Ambry Genetics
  • muscular dystrophy-dystroglycanopathy type B5
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Myriad Women’s Health, Labcorp Genetics (formerly Invitae)
  • myopathy caused by variation in FKRP
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • congenital muscular dystrophy with cerebellar involvement
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • congenital muscular dystrophy with intellectual disability
    Inheritance: AR 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 22 uncertain in NM_024301.5
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 46 curated pathogenic missense variants (we use a threshold of 10). The gene has 2 curated benign missense variants. Gene score misZ: 1.8498 (below the threshold of 3.09). Trascript score misZ: -2.4986 (below the threshold of 3.09). GenCC associations: The gene is linked to autosomal recessive limb-girdle muscular dystrophy type 2I, muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A5, congenital muscular dystrophy with intellectual disability, muscular dystrophy-dystroglycanopathy, type A, muscle-eye-brain disease, congenital muscular dystrophy with cerebellar involvement, myopathy caused by variation in FKRP, muscular dystrophy-dystroglycanopathy type B5, congenital muscular dystrophy without intellectual disability.
BP4
Computational evidence support a benign effect (MetaRNN=0.29710004).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FKRPNM_024301.5 linkc.554C>T p.Ala185Val 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
FKRPENST00000318584.10 linkc.554C>T p.Ala185Val missense_variant Exon 4 of 4 1 NM_024301.5 ENSP00000326570.4 Q9H9S5

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
151886
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
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
GnomAD2 exomes
AF:
0.00
AC:
0
AN:
160354
AF XY:
0.00
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
7.12e-7
AC:
1
AN:
1405052
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
696196
show subpopulations
African (AFR)
AF:
0.0000314
AC:
1
AN:
31862
American (AMR)
AF:
0.00
AC:
0
AN:
38500
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25190
East Asian (EAS)
AF:
0.00
AC:
0
AN:
36962
South Asian (SAS)
AF:
0.00
AC:
0
AN:
80844
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
35296
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5712
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1092120
Other (OTH)
AF:
0.00
AC:
0
AN:
58566
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000132
AC:
2
AN:
151886
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74190
show subpopulations
African (AFR)
AF:
0.0000483
AC:
2
AN:
41378
American (AMR)
AF:
0.00
AC:
0
AN:
15262
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5150
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10588
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67900
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2I Uncertain:1
Oct 01, 2021
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Cardiovascular phenotype Uncertain:1
Aug 20, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A185V variant (also known as c.554C>T), located in coding exon 1 of the FKRP gene, results from a C to T substitution at nucleotide position 554. The alanine at codon 185 is replaced by valine, an amino acid with similar properties. This amino acid position is conserved. 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
Jul 19, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 185 of the FKRP protein (p.Ala185Val). This variant is present in population databases (no rsID available, gnomAD 0.006%). 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: 528812). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
BayesDel_addAF
Uncertain
0.051
T
BayesDel_noAF
Benign
-0.17
CADD
Benign
17
DANN
Uncertain
0.98
DEOGEN2
Benign
0.19
T;T
Eigen
Benign
-0.66
Eigen_PC
Benign
-0.61
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Benign
0.64
.;T
M_CAP
Pathogenic
0.55
D
MetaRNN
Benign
0.30
T;T
MetaSVM
Pathogenic
0.93
D
MutationAssessor
Benign
1.2
L;L
PhyloP100
2.0
PrimateAI
Pathogenic
0.88
D
PROVEAN
Benign
-0.31
N;N
REVEL
Uncertain
0.40
Sift
Benign
0.062
T;T
Sift4G
Benign
0.14
T;T
Polyphen
0.0070
B;B
Vest4
0.26
MutPred
0.28
Loss of glycosylation at P186 (P = 0.0874);Loss of glycosylation at P186 (P = 0.0874);
MVP
0.88
MPC
0.67
ClinPred
0.14
T
GERP RS
3.5
Varity_R
0.14
gMVP
0.66
Mutation Taster
=74/26
polymorphism

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

Other links and lift over

dbSNP: rs1032563159; hg19: chr19-47259261; API