rs939213590

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_001101426.4(CRPPA):​c.226C>G​(p.Leu76Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000116 in 1,298,676 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000052 ( 0 hom. )

Consequence

CRPPA
NM_001101426.4 missense

Scores

4
8
7

Clinical Significance

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

Conservation

PhyloP100: 6.65

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 0 ACMG points.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CRPPANM_001101426.4 linkc.226C>G p.Leu76Val missense_variant Exon 1 of 10 ENST00000407010.7 NP_001094896.1 A4D126-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CRPPAENST00000407010.7 linkc.226C>G p.Leu76Val missense_variant Exon 1 of 10 5 NM_001101426.4 ENSP00000385478.2 A4D126-1

Frequencies

GnomAD3 genomes
AF:
0.0000592
AC:
9
AN:
152088
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000217
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
GnomAD4 exome
AF:
0.00000523
AC:
6
AN:
1146588
Hom.:
0
Cov.:
31
AF XY:
0.00000546
AC XY:
3
AN XY:
549628
show subpopulations
African (AFR)
AF:
0.000256
AC:
6
AN:
23450
American (AMR)
AF:
0.00
AC:
0
AN:
9134
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
15304
East Asian (EAS)
AF:
0.00
AC:
0
AN:
26888
South Asian (SAS)
AF:
0.00
AC:
0
AN:
33888
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
38814
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4698
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
948520
Other (OTH)
AF:
0.00
AC:
0
AN:
45892
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000592
AC:
9
AN:
152088
Hom.:
0
Cov.:
33
AF XY:
0.0000673
AC XY:
5
AN XY:
74300
show subpopulations
African (AFR)
AF:
0.000217
AC:
9
AN:
41428
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5148
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67990
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.469
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

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:
0.000214
Hom.:
0
Bravo
AF:
0.000132

ClinVar

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

Submissions by phenotype

not specified Uncertain:2
Feb 01, 2017
Genetic Services Laboratory, University of Chicago
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 24, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.226C>G (p.L76V) alteration is located in exon 1 (coding exon 1) of the ISPD gene. This alteration results from a C to G substitution at nucleotide position 226, causing the leucine (L) at amino acid position 76 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 7;C5190987:Autosomal recessive limb-girdle muscular dystrophy type 2U Uncertain:1
Sep 24, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces leucine with valine at codon 76 of the ISPD protein (p.Leu76Val). The leucine residue is highly conserved and there is a small physicochemical difference between leucine and valine. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate insufficient coverage at this position in the ExAC database. This variant has not been reported in the literature in individuals with ISPD-related conditions. ClinVar contains an entry for this variant (Variation ID: 435528). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). 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
0.16
BayesDel_addAF
Pathogenic
0.19
D
BayesDel_noAF
Uncertain
0.040
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Benign
0.36
T;.
Eigen
Uncertain
0.45
Eigen_PC
Uncertain
0.48
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.89
D;D
M_CAP
Pathogenic
0.65
D
MetaRNN
Uncertain
0.57
D;D
MetaSVM
Uncertain
0.22
D
MutationAssessor
Benign
1.2
L;L
PhyloP100
6.6
PrimateAI
Uncertain
0.69
T
PROVEAN
Benign
-1.9
N;N
REVEL
Pathogenic
0.65
Sift
Benign
0.23
T;T
Sift4G
Benign
0.099
T;T
Polyphen
0.97
D;.
Vest4
0.47
MVP
0.76
MPC
0.12
ClinPred
0.96
D
GERP RS
4.5
PromoterAI
-0.033
Neutral
Varity_R
0.73
gMVP
0.64
Mutation Taster
=16/84
disease causing

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: rs939213590; hg19: chr7-16460722; API