rs1281394588

Positions:

• chr8-67746009-C-G
• chr8-67746009-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_020361.5(CPA6):​c.116+5G>C variant causes a splice donor 5th base, intron change. 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 predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CPA6 NM_020361.5 splice_donor_5th_base, intron
• Scores: Splicing: ADA: 0.9995
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.96

Genes affected

CPA6 (HGNC:17245): (carboxypeptidase A6) The gene encodes a member of the peptidase M14 family of metallocarboxypeptidases. The encoded preproprotein is proteolytically processed to generate the mature enzyme, which catalyzes the release of large hydrophobic C-terminal amino acids. This enzyme has functions ranging from digestion of food to selective biosynthesis of neuroendocrine peptides. Mutations in this gene may be linked to epilepsy and febrile seizures, and a translocation t(6;8)(q26;q13) involving this gene has been associated with Duane retraction syndrome. [provided by RefSeq, May 2016]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CPA6	NM_020361.5	c.116+5G>C		splice_donor_5th_base_variant, intron_variant		ENST00000297770.10
CPA6	XM_017013646.2	c.-291+5G>C		splice_donor_5th_base_variant, intron_variant
CPA6	XM_017013647.2	c.116+5G>C		splice_donor_5th_base_variant, intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CPA6	ENST00000297770.10	c.116+5G>C		splice_donor_5th_base_variant, intron_variant		1	NM_020361.5	P1
CPA6	ENST00000479862.6	c.116+5G>C		splice_donor_5th_base_variant, intron_variant, NMD_transcript_variant		1
CPA6	ENST00000518549.1	n.330+5G>C		splice_donor_5th_base_variant, intron_variant, non_coding_transcript_variant		1
CPA6	ENST00000638254.1	c.116+5G>C		splice_donor_5th_base_variant, intron_variant, NMD_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Febrile seizures, familial, 11 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 21, 2017

In summary, this is a novel intronic change with uncertain impact on splicing. It has been classified as a Variant of Uncertain Significance. Nucleotide substitutions within the consensus splice site are relatively common causes of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of nucleotide changes on RNA splicing suggest that this variant may alter RNA splicing, but this prediction has not been confirmed by published transcriptional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a CPA6-related disease. This sequence change falls in intron 1 of the CPA6 gene. It does not directly change the encoded amino acid sequence of the CPA6 protein, but it affects a nucleotide within the consensus splice site of the intron. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.21
CADD	Benign	23
DANN	Uncertain	0.97

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.99
SpliceAI score (max)		0.44		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.44		Position offset: 5

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

Publications

LitVar

Other links and lift over

dbSNP: rs1281394588; hg19: chr8-68658244;