chr5-140795382-A-C

Position:

• chr5-140795382-A-C

Variant summary

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

The NM_018905.3(PCDHA2):​c.418A>C​(p.Ile140Leu) variant causes a missense 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. 15/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I140M) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: PCDHA2 NM_018905.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.998

Genes affected

PCDHA2 (HGNC:8668): (protocadherin alpha 2) This gene is a member of the protocadherin alpha gene cluster, one of three related gene clusters tandemly linked on chromosome five that demonstrate an unusual genomic organization similar to that of B-cell and T-cell receptor gene clusters. The alpha gene cluster is composed of 15 cadherin superfamily genes related to the mouse CNR genes and consists of 13 highly similar and 2 more distantly related coding sequences. The tandem array of 15 N-terminal exons, or variable exons, are followed by downstream C-terminal exons, or constant exons, which are shared by all genes in the cluster. The large, uninterrupted N-terminal exons each encode six cadherin ectodomains while the C-terminal exons encode the cytoplasmic domain. These neural cadherin-like cell adhesion proteins are integral plasma membrane proteins that most likely play a critical role in the establishment and function of specific cell-cell connections in the brain. Alternative splicing has been observed and additional variants have been suggested but their full-length nature has yet to be determined. [provided by RefSeq, Jul 2008]

PCDHA1 (HGNC:8663): (protocadherin alpha 1) This gene is a member of the protocadherin alpha gene cluster, one of three related gene clusters tandemly linked on chromosome five that demonstrate an unusual genomic organization similar to that of B-cell and T-cell receptor gene clusters. The alpha gene cluster is composed of 15 cadherin superfamily genes related to the mouse CNR genes and consists of 13 highly similar and 2 more distantly related coding sequences. The tandem array of 15 N-terminal exons, or variable exons, are followed by downstream C-terminal exons, or constant exons, which are shared by all genes in the cluster. The large, uninterrupted N-terminal exons each encode six cadherin ectodomains while the C-terminal exons encode the cytoplasmic domain. These neural cadherin-like cell adhesion proteins are integral plasma membrane proteins that most likely play a critical role in the establishment and function of specific cell-cell connections in the brain. Alternative splicing has been observed and additional variants have been suggested but their full-length nature has yet to be determined. [provided by RefSeq, Jul 2008]

(HGNC:):

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 (MetaRNN=0.050406545).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PCDHA2	NM_018905.3	c.418A>C	p.Ile140Leu	missense_variant	1/4	ENST00000526136.2
PCDHA1	NM_018900.4	c.2394+6698A>C		intron_variant		ENST00000504120.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PCDHA2	ENST00000526136.2	c.418A>C	p.Ile140Leu	missense_variant	1/4	1	NM_018905.3	P1
PCDHA1	ENST00000504120.4	c.2394+6698A>C		intron_variant		1	NM_018900.4	P1
	ENST00000655235.1	n.658-6528T>G		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251496 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135922

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 03, 2024

The c.418A>C (p.I140L) alteration is located in exon 1 (coding exon 1) of the PCDHA2 gene. This alteration results from a A to C substitution at nucleotide position 418, causing the isoleucine (I) at amino acid position 140 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.086
BayesDel_addAF	Benign	-0.25	T
BayesDel_noAF	Benign	-0.59
CADD	Benign	0.089
DANN	Benign	0.56
DEOGEN2	Benign	0.0037	.;.;T
Eigen	Benign	-1.8
Eigen_PC	Benign	-1.8
FATHMM_MKL	Benign	0.016	N
LIST_S2	Benign	0.30	T;T;T
M_CAP	Benign	0.0046	T
MetaRNN	Benign	0.050	T;T;T
MetaSVM	Benign	-0.96	T
MutationAssessor	Benign	-1.5	N;N;N
MutationTaster	Benign	1.0	N;N;N;N;N
PROVEAN	Benign	1.1	N;N;N
REVEL	Benign	0.076
Sift	Benign	1.0	T;T;T
Sift4G	Benign	1.0	T;T;T
Polyphen		0.0030	B;B;B
Vest4		0.12
MutPred		0.47		Loss of methylation at K138 (P = 0.0817);Loss of methylation at K138 (P = 0.0817);Loss of methylation at K138 (P = 0.0817);
MVP		0.34
ClinPred		0.041	T
GERP RS		-4.1
Varity_R		0.052
gMVP		0.19

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: rs1387448123; hg19: chr5-140174967;