7-16406249-G-C

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2BP4

The NM_001101426.4(CRPPA):​c.346C>G​(p.Arg116Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,628 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict 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. R116H) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

CRPPA
NM_001101426.4 missense

Scores

1
4
14

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.63

Publications

0 publications found
Variant links:
Genes affected
CRPPA (HGNC:37276): (CDP-L-ribitol pyrophosphorylase A) This gene encodes a 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase-like protein. Mutations in this gene are the cause of Walker-Warburg syndrome. Alternate splicing results in multiple transcript variants. [provided by RefSeq, May 2012]
CRPPA Gene-Disease associations (from GenCC):
  • muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 7
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
  • myopathy caused by variation in CRPPA
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • autosomal recessive limb-girdle muscular dystrophy type 2U
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • congenital muscular dystrophy without intellectual disability
    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 1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.3573867).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CRPPANM_001101426.4 linkc.346C>G p.Arg116Gly missense_variant Exon 2 of 10 ENST00000407010.7 NP_001094896.1 A4D126-1
CRPPANM_001368197.1 linkc.346C>G p.Arg116Gly missense_variant Exon 2 of 9 NP_001355126.1
CRPPANM_001101417.4 linkc.346C>G p.Arg116Gly missense_variant Exon 2 of 9 NP_001094887.1 A4D126-2A0A140VJM1
CRPPANR_160656.1 linkn.562C>G non_coding_transcript_exon_variant Exon 2 of 8

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CRPPAENST00000407010.7 linkc.346C>G p.Arg116Gly missense_variant Exon 2 of 10 5 NM_001101426.4 ENSP00000385478.2 A4D126-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000803
AC:
2
AN:
249070
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000290
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:
0.000165
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461628
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
727092
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.0000224
AC:
1
AN:
44712
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53396
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111818
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60372
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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
Cov.:
33
ExAC
AF:
0.00000828
AC:
1

ClinVar

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

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 7;C5190987:Autosomal recessive limb-girdle muscular dystrophy type 2U Uncertain:1
Apr 18, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C45". The glycine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. This variant has not been reported in the literature in individuals affected with ISPD-related conditions. This variant is present in population databases (rs61744487, gnomAD 0.003%). This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 116 of the ISPD protein (p.Arg116Gly). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Benign
-0.094
T
BayesDel_noAF
Benign
-0.29
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.57
D;.
Eigen
Benign
-0.077
Eigen_PC
Benign
-0.18
FATHMM_MKL
Benign
0.61
D
LIST_S2
Benign
0.68
T;T
M_CAP
Benign
0.065
D
MetaRNN
Benign
0.36
T;T
MetaSVM
Benign
-0.32
T
MutationAssessor
Benign
1.6
L;L
PhyloP100
1.6
PrimateAI
Benign
0.29
T
PROVEAN
Pathogenic
-4.7
D;D
REVEL
Benign
0.29
Sift
Uncertain
0.0040
D;D
Sift4G
Uncertain
0.0050
D;D
Polyphen
0.99
D;.
Vest4
0.28
MutPred
0.62
Loss of MoRF binding (P = 0.0406);Loss of MoRF binding (P = 0.0406);
MVP
0.65
MPC
0.083
ClinPred
0.92
D
GERP RS
0.060
Varity_R
0.78
gMVP
0.66
Mutation Taster
=53/47
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: rs61744487; hg19: chr7-16445874; API