8-67624243-A-G

Variant names:

• chr8-67624243-A-G
• rs1554526426
• NM_020361.5:c.125T>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_020361.5(CPA6):​c.125T>C​(p.Val42Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. V42V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CPA6 NM_020361.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.26
• Publications: 0 publications found

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]

CPA6 Gene-Disease associations (from GenCC):

• benign familial mesial temporal lobe epilepsy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial mesial temporal lobe epilepsy with febrile seizures

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial temporal lobe epilepsy 5

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• febrile seizures, familial, 11

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
• epilepsy

  Inheritance: AD, AR Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.752

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CPA6	NM_020361.5	c.125T>C	p.Val42Ala	missense_variant	Exon 2 of 11	ENST00000297770.10	NP_065094.3
CPA6	NM_001440615.1	c.125T>C	p.Val42Ala	missense_variant	Exon 2 of 7		NP_001427544.1
CPA6	XM_017013646.2	c.-195T>C		5_prime_UTR_variant	Exon 3 of 11		XP_016869135.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CPA6	ENST00000297770.10	c.125T>C	p.Val42Ala	missense_variant	Exon 2 of 11	1	NM_020361.5	ENSP00000297770.4
CPA6	ENST00000479862.6	n.125T>C		non_coding_transcript_exon_variant	Exon 2 of 8	1		ENSP00000419016.2
CPA6	ENST00000518549.1	n.339T>C		non_coding_transcript_exon_variant	Exon 2 of 8	1
CPA6	ENST00000638254.1	n.125T>C		non_coding_transcript_exon_variant	Exon 2 of 10	5		ENSP00000491129.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1311786 Hom.: 0 Cov.: 21 AF XY: 0.00 AC XY: 0 AN XY: 659878

African (AFR) AF: 0.00 AC: 0 AN: 29908

American (AMR) AF: 0.00 AC: 0 AN: 42010

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25076

East Asian (EAS) AF: 0.00 AC: 0 AN: 38954

South Asian (SAS) AF: 0.00 AC: 0 AN: 80794

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52918

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5456

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 981240

Other (OTH) AF: 0.00 AC: 0 AN: 55430

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Febrile seizures, familial, 11 Uncertain:1

Jul 19, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 539977). This variant has not been reported in the literature in individuals affected with CPA6-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces valine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 42 of the CPA6 protein (p.Val42Ala). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.82
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.020
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.15	T
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Benign	0.67	T
M_CAP	Benign	0.036	D
MetaRNN	Pathogenic	0.75	D
MetaSVM	Benign	-0.73	T
MutationAssessor	Benign	0.0	N
PhyloP100		4.3
PrimateAI	Uncertain	0.57	T
PROVEAN	Uncertain	-3.4	D
REVEL	Uncertain	0.36
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.034	D
Polyphen		1.0	D
Vest4		0.61
MutPred		0.65		Loss of methylation at K41 (P = 0.035);
MVP		0.67
MPC		0.072
ClinPred		0.88	D
GERP RS		5.4
Varity_R		0.44
gMVP		0.66
Mutation Taster		=220/80	polymorphism

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

Other links and lift over

dbSNP: rs1554526426; hg19: chr8-68536478;