chr7-16216062-C-T

Variant names:

• chr7-16216062-C-T
• rs753402341
• NM_001101426.4:c.1251+4G>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001101426.4(CRPPA):​c.1251+4G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000114 in 1,574,604 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000011 (0 hom.)
• Consequence: CRPPA NM_001101426.4 splice_region, intron
• Scores: Splicing: ADA: 0.0001825
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -1.27
• Publications: 0 publications found

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

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.73).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRPPA	NM_001101426.4	c.1251+4G>A		splice_region_variant, intron_variant	Intron 9 of 9	ENST00000407010.7	NP_001094896.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRPPA	ENST00000407010.7	c.1251+4G>A		splice_region_variant, intron_variant	Intron 9 of 9	5	NM_001101426.4	ENSP00000385478.2

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152140 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

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: 0.0000441

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000136 AC: 3 AN: 221162 AF XY: 0.0000166

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: 0.0000287

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000105 AC: 15 AN: 1422464 Hom.: 0 Cov.: 26 AF XY: 0.0000155 AC XY: 11 AN XY: 707858

African (AFR) AF: 0.00 AC: 0 AN: 31216

American (AMR) AF: 0.00 AC: 0 AN: 36518

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24272

East Asian (EAS) AF: 0.00 AC: 0 AN: 39098

South Asian (SAS) AF: 0.00 AC: 0 AN: 79950

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52752

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5248

European-Non Finnish (NFE) AF: 0.0000128 AC: 14 AN: 1094778

Other (OTH) AF: 0.0000171 AC: 1 AN: 58632

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152140 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74330

African (AFR) AF: 0.00 AC: 0 AN: 41430

American (AMR) AF: 0.00 AC: 0 AN: 15278

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: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10604

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000441 AC: 3 AN: 68022

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000227

EpiCase AF: 0.000166

EpiControl AF: 0.0000601

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Jul 01, 2016

CeGaT Center for Human Genetics Tuebingen

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Congenital Muscular Dystrophy, alpha-dystroglycan related Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.73
CADD	Benign	12
DANN	Benign	0.84
PhyloP100		-1.3

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00018
dbscSNV1_RF	Benign	0.084
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

Other links and lift over

dbSNP: rs753402341; hg19: chr7-16255687; COSMIC: COSV67906593;