7-16087903-T-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001101426.4(CRPPA):c.*3792A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000138 in 152,304 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.00014 (0 hom., cov: 32)
• Consequence: CRPPA NM_001101426.4 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.928

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.84).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CRPPA	NM_001101426.4	c.*3792A>G		3_prime_UTR_variant	10/10	ENST00000407010.7
CRPPA	NM_001101417.4	c.*3792A>G		3_prime_UTR_variant	9/9
CRPPA	NM_001368197.1	c.*3792A>G		3_prime_UTR_variant	9/9
CRPPA	NR_160656.1	n.5213A>G		non_coding_transcript_exon_variant	8/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CRPPA	ENST00000407010.7	c.*3792A>G		3_prime_UTR_variant	10/10	5	NM_001101426.4	P1

Frequencies

GnomAD3 genomes AF: 0.000138 AC: 21 AN: 152186 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00231

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000735

Gnomad OTH AF: 0.000955

GnomAD4 exome Cov.: 0

GnomAD4 genome AF: 0.000138 AC: 21 AN: 152304 Hom.: 0 Cov.: 32 AF XY: 0.000161 AC XY: 12 AN XY: 74484

Gnomad4 AFR AF: 0.0000481

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00231

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000735

Gnomad4 OTH AF: 0.000945

Bravo AF: 0.000136

Asia WGS AF: 0.00115 AC: 4 AN: 3476

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital Muscular Dystrophy, alpha-dystroglycan related Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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	-0.84
Cadd	Benign	1.7
Dann	Benign	0.81

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: rs544136100; hg19: chr7-16127528;