7-16216093-T-A

Variant names:

• chr7-16216093-T-A
• rs931469039
• NM_001101426.4:c.1224A>T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_001101426.4(CRPPA):​c.1224A>T​(p.Leu408Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000484 in 1,447,224 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: CRPPA NM_001101426.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.617

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-AS1 (HGNC:48962): (CRPPA antisense RNA 1)

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3485024).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRPPA	NM_001101426.4	c.1224A>T	p.Leu408Phe	missense_variant	Exon 9 of 10	ENST00000407010.7	NP_001094896.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRPPA	ENST00000407010.7	c.1224A>T	p.Leu408Phe	missense_variant	Exon 9 of 10	5	NM_001101426.4	ENSP00000385478.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000828 AC: 2 AN: 241434 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 130714

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000608

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS 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: 0.00000484 AC: 7 AN: 1447224 Hom.: 0 Cov.: 27 AF XY: 0.00000556 AC XY: 4 AN XY: 720016

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000699

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000362

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Nov 25, 2021

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 7;C5190987:Autosomal recessive limb-girdle muscular dystrophy type 2U Uncertain:1

Jul 19, 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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 1680743). This variant has not been reported in the literature in individuals affected with ISPD-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.006%). This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 408 of the ISPD protein (p.Leu408Phe). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Benign	-0.070	T
BayesDel_noAF	Benign	-0.16
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Benign	0.025	T;.
Eigen	Benign	0.16
Eigen_PC	Benign	0.14
FATHMM_MKL	Benign	0.63	D
LIST_S2	Benign	0.85	D;T
M_CAP	Uncertain	0.23	D
MetaRNN	Benign	0.35	T;T
MetaSVM	Uncertain	0.40	D
MutationAssessor	Uncertain	2.2	M;.
PrimateAI	Benign	0.48	T
PROVEAN	Benign	-1.4	N;N
REVEL	Uncertain	0.34
Sift	Uncertain	0.0050	D;D
Sift4G	Uncertain	0.016	D;D
Polyphen		1.0	D;.
Vest4		0.32
MutPred		0.27		Loss of sheet (P = 0.0181);.;
MVP		0.68
MPC		0.36
ClinPred		0.80	D
GERP RS		3.9
Varity_R		0.31
gMVP		0.56

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

LitVar

Other links and lift over

dbSNP: rs931469039; hg19: chr7-16255718;