NM_018938.4:c.491A>G

Variant names:

• chr5-141122489-A-G
• rs868919336
• NM_018938.4:c.491A>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_018938.4(PCDHB4):​c.491A>G​(p.Asn164Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000434 in 1,614,098 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: PCDHB4 NM_018938.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.00
• Publications: 0 publications found

Genes affected

PCDHB4 (HGNC:8689): (protocadherin beta 4) This gene is a member of the protocadherin beta gene cluster, one of three related gene clusters tandemly linked on chromosome five. The gene clusters demonstrate an unusual genomic organization similar to that of B-cell and T-cell receptor gene clusters. The beta cluster contains 16 genes and 3 pseudogenes, each encoding 6 extracellular cadherin domains and a cytoplasmic tail that deviates from others in the cadherin superfamily. The extracellular domains interact in a homophilic manner to specify differential cell-cell connections. Unlike the alpha and gamma clusters, the transcripts from these genes are made up of only one large exon, not sharing common 3' exons as expected. These neural cadherin-like cell adhesion proteins are integral plasma membrane proteins. Their specific functions are unknown but they most likely play a critical role in the establishment and function of specific cell-cell neural connections. [provided by RefSeq, Jul 2008]

PCDHB@ (HGNC:8679):

ENSG00000272154 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.941

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PCDHB4	NM_018938.4	c.491A>G	p.Asn164Ser	missense_variant	Exon 1 of 1	ENST00000194152.4	NP_061761.1
PCDHB@		n.141122489A>G		intragenic_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PCDHB4	ENST00000194152.4	c.491A>G	p.Asn164Ser	missense_variant	Exon 1 of 1	6	NM_018938.4	ENSP00000194152.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152212 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461886 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727242

African (AFR) AF: 0.000119 AC: 4 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.000173 AC: 1 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152212 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74368

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000241 AC: 1 AN: 41460

American (AMR) AF: 0.00 AC: 0 AN: 15282

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

South Asian (SAS) AF: 0.00 AC: 0 AN: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10624

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68024

Other (OTH) AF: 0.00 AC: 0 AN: 2094

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Aug 09, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.491A>G (p.N164S) alteration is located in exon 1 (coding exon 1) of the PCDHB4 gene. This alteration results from a A to G substitution at nucleotide position 491, causing the asparagine (N) at amino acid position 164 to be replaced by a serine (S). 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	0.14
BayesDel_addAF	Benign	-0.038	T
BayesDel_noAF	Benign	-0.29
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Benign	0.16	T
Eigen	Pathogenic	0.73
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Benign	0.043	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Uncertain	0.53	D
MutationAssessor	Pathogenic	3.2	M
PhyloP100		4.0
PrimateAI	Benign	0.43	T
PROVEAN	Pathogenic	-4.8	D
REVEL	Uncertain	0.36
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.68
MutPred		0.77		Gain of glycosylation at N164 (P = 0.0105);
MVP		0.71
ClinPred		0.98	D
GERP RS		4.6
Varity_R		0.58
gMVP		0.40
Mutation Taster		=89/11	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: rs868919336; hg19: chr5-140502071;