chr7-16088321-G-A

Position:

• chr7-16088321-G-A

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_Strong BP6_Moderate BS1 BS2

The NM_001101426.4(CRPPA):​c.*3374C>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00638 in 151,606 control chromosomes in the GnomAD database, including 8 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0064 (8 hom., cov: 32)
  • Failed GnomAD Quality Control
• Consequence: CRPPA NM_001101426.4 3_prime_UTR
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -1.49

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 Benign. Variant got -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.89).
• BP6: Variant 7-16088321-G-A is Benign according to our data. Variant chr7-16088321-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 908676.Status of the report is criteria_provided_single_submitter, 1 stars.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00638 (968/151606) while in subpopulation AFR AF= 0.0219 (906/41324). AF 95% confidence interval is 0.0207. There are 8 homozygotes in gnomad4. There are 438 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd4 at 8 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CRPPA	NM_001101426.4	c.*3374C>T		3_prime_UTR_variant	10/10	ENST00000407010.7	NP_001094896.1
CRPPA	NM_001101417.4	c.*3374C>T		3_prime_UTR_variant	9/9		NP_001094887.1
CRPPA	NM_001368197.1	c.*3374C>T		3_prime_UTR_variant	9/9		NP_001355126.1
CRPPA	NR_160656.1	n.4795C>T		non_coding_transcript_exon_variant	8/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CRPPA	ENST00000407010.7	c.*3374C>T		3_prime_UTR_variant	10/10	5	NM_001101426.4	ENSP00000385478	P1

Frequencies

GnomAD3 genomes AF: 0.00637 AC: 965 AN: 151510 Hom.: 8 Cov.: 32

Gnomad AFR AF: 0.0219

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00296

Gnomad ASJ AF: 0.00173

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00384

GnomAD4 exome Data not reliable, filtered out with message: AC0 AC: 0 AN: 0 Hom.: 0 Cov.: 0 AC XY: 0 AN XY: 0

GnomAD4 genome AF: 0.00638 AC: 968 AN: 151606 Hom.: 8 Cov.: 32 AF XY: 0.00592 AC XY: 438 AN XY: 74034

Gnomad4 AFR AF: 0.0219

Gnomad4 AMR AF: 0.00296

Gnomad4 ASJ AF: 0.00173

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00380

Alfa AF: 0.00476 Hom.: 3

Bravo AF: 0.00743

Asia WGS AF: 0.000866 AC: 3 AN: 3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital Muscular Dystrophy, alpha-dystroglycan related Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 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 and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.89
CADD	Benign	0.42
DANN	Benign	0.53

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: rs141198656; hg19: chr7-16127946;