chr19-46756585-C-CG

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_024301.5(FKRP):​c.1141dupG​(p.Ala381GlyfsTer9) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000994 in 1,610,046 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. A381A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

FKRP
NM_024301.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 3.60

Publications

1 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: Pathogenic. The variant received 18 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 51 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 19-46756585-C-CG is Pathogenic according to our data. Variant chr19-46756585-C-CG is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 556419.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
FKRPNM_024301.5 linkc.1141dupG p.Ala381GlyfsTer9 frameshift_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.1141dupG p.Ala381GlyfsTer9 frameshift_variant Exon 4 of 4 1 NM_024301.5 ENSP00000326570.4 Q9H9S5
FKRPENST00000391909.7 linkc.1141dupG p.Ala381GlyfsTer9 frameshift_variant Exon 4 of 4 2 ENSP00000375776.2 Q9H9S5
FKRPENST00000597339.5 linkn.247-5242dupG intron_variant Intron 3 of 3 5
FKRPENST00000600646.5 linkn.247+7926dupG intron_variant Intron 3 of 3 3

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152036
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000242
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00
AC:
0
AN:
238782
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:
0.00000960
AC:
14
AN:
1458010
Hom.:
0
Cov.:
32
AF XY:
0.00000552
AC XY:
4
AN XY:
725078
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33456
American (AMR)
AF:
0.00
AC:
0
AN:
43856
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25914
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39574
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85534
European-Finnish (FIN)
AF:
0.0000946
AC:
5
AN:
52836
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.00000720
AC:
8
AN:
1110810
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60268
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.429
Heterozygous variant carriers
0
1
2
2
3
4
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:
152036
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74272
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41406
American (AMR)
AF:
0.00
AC:
0
AN:
15264
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4802
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10610
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67992
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
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

Age Distribution

Genome 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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000151

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2I Pathogenic:2
Feb 05, 2018
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Mar 03, 2021
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

not provided Pathogenic:1
Feb 17, 2022
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Observed with a second FKRP variant in multiple individuals described with limb-girdle muscular dystrophy, although it is not known if the second FKRP variant is on the opposite allele (in trans) or on the same allele (in cis) (Ghaoui R et al., 2015; Song D et al., 2021); Frameshift variant predicted to result in protein truncation, as the last 115 amino acids are replaced with 8 different amino acids, and other loss-of-function variants have been reported downstream in HGMD.; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 27439679, 26436962, 33200426) -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A5 Pathogenic:1
Nov 11, 2022
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Walker-Warburg congenital muscular dystrophy Pathogenic:1
Oct 15, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Ala381Glyfs*9) in the FKRP gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 115 amino acid(s) of the FKRP protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with limb girdle muscular dystrophy (PMID: 26436962). This variant is also known as c.1140_1141insG. ClinVar contains an entry for this variant (Variation ID: 556419). This variant disrupts a region of the FKRP protein in which other variant(s) (p.Ser385*) have been determined to be pathogenic (PMID: 11592034, 12666124, 12707425, 14742276). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
3.6
Mutation Taster
=0/200
disease causing (ClinVar)

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: rs754403441; hg19: chr19-47259842; COSMIC: COSV100586669; COSMIC: COSV100586669; API