rs970724879

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 5P and 2B. PM1PM2PP2BP4_Moderate

The NM_024301.5(FKRP):​c.516C>A​(p.Asn172Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000039 in 1,538,782 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. N172N) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000036 ( 0 hom. )

Consequence

FKRP
NM_024301.5 missense

Scores

2
2
14

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -0.0200

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 3 ACMG points.

PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 12 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=0.1380417).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FKRPNM_024301.5 linkc.516C>A p.Asn172Lys missense_variant Exon 4 of 4 ENST00000318584.10 NP_077277.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
FKRPENST00000318584.10 linkc.516C>A p.Asn172Lys missense_variant Exon 4 of 4 1 NM_024301.5 ENSP00000326570.4

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152172
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00000743
AC:
1
AN:
134524
AF XY:
0.0000135
show subpopulations
Gnomad AFR exome
AF:
0.000157
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:
0.00000361
AC:
5
AN:
1386610
Hom.:
0
Cov.:
32
AF XY:
0.00000146
AC XY:
1
AN XY:
684964
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31434
American (AMR)
AF:
0.00
AC:
0
AN:
35908
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25058
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35942
South Asian (SAS)
AF:
0.00
AC:
0
AN:
79364
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
34440
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5686
European-Non Finnish (NFE)
AF:
0.00000370
AC:
4
AN:
1080856
Other (OTH)
AF:
0.0000173
AC:
1
AN:
57922
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.515
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.00000657
AC:
1
AN:
152172
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74334
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41458
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67998
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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:
0.00000756

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Walker-Warburg congenital muscular dystrophy Uncertain:1
Jun 22, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces asparagine, which is neutral and polar, with lysine, which is basic and polar, at codon 172 of the FKRP protein (p.Asn172Lys). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with FKRP-related conditions. 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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
0.32
BayesDel_addAF
Benign
-0.014
T
BayesDel_noAF
Benign
-0.26
CADD
Benign
8.4
DANN
Benign
0.34
DEOGEN2
Benign
0.23
T;T;.
Eigen
Benign
-1.1
Eigen_PC
Benign
-1.0
FATHMM_MKL
Benign
0.68
D
LIST_S2
Benign
0.0
.;T;T
M_CAP
Pathogenic
0.51
D
MetaRNN
Benign
0.14
T;T;T
MetaSVM
Uncertain
0.21
D
MutationAssessor
Benign
-0.69
N;N;.
PhyloP100
-0.020
PrimateAI
Pathogenic
0.96
D
PROVEAN
Benign
-0.56
N;N;.
REVEL
Uncertain
0.36
Sift
Benign
0.56
T;T;.
Sift4G
Benign
0.91
T;T;D
Vest4
0.15
ClinPred
0.014
T
GERP RS
-3.2
Varity_R
0.20
gMVP
0.55
Mutation Taster
=50/50

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: rs970724879; hg19: chr19-47259223; API