chr7-16278124-C-G

Variant names:

• chr7-16278124-C-G
• rs1554305652
• NM_001101426.4:c.933+5G>C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001101426.4(CRPPA):​c.933+5G>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CRPPA NM_001101426.4 splice_region, intron
• Scores: Splicing: ADA: 0.9545
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.09
• 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 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

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.31).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CRPPA	NM_001101426.4	c.933+5G>C		splice_region_variant, intron_variant	Intron 6 of 9	ENST00000407010.7	NP_001094896.1
CRPPA	NM_001368197.1	c.828+5G>C		splice_region_variant, intron_variant	Intron 5 of 8		NP_001355126.1
CRPPA	NM_001101417.4	c.783+5G>C		splice_region_variant, intron_variant	Intron 5 of 8		NP_001094887.1
CRPPA	NR_160656.1	n.998+5G>C		splice_region_variant, intron_variant	Intron 4 of 7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CRPPA	ENST00000407010.7	c.933+5G>C		splice_region_variant, intron_variant	Intron 6 of 9	5	NM_001101426.4	ENSP00000385478.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 18

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 7 Uncertain:1

Feb 22, 2018

Center For Human Genetics And Laboratory Diagnostics, Dr. Klein, Dr. Rost And Colleagues

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.31
CADD	Pathogenic	26
DANN	Benign	0.91
PhyloP100		2.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.95
dbscSNV1_RF	Benign	0.67
SpliceAI score (max)		0.63		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.63		Position offset: 47
DS_DL_spliceai		0.46		Position offset: 5

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1554305652; hg19: chr7-16317749;