6-155275958-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001001346.3(CLDN20):c.239C>T(p.Ala80Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000141 in 1,614,038 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 0.00012 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00014 (0 hom.)
• Consequence: CLDN20 NM_001001346.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.57

Genes affected

CLDN20 (HGNC:2042): (claudin 20) This gene encodes a member of the claudin family. Claudins are integral membrane proteins and components of tight junction strands. Tight junction strands serve as a physical barrier to prevent solutes and water from passing freely through the paracellular space between epithelial or endothelial cell sheets, and also play critical roles in maintaining cell polarity and signal transductions. [provided by RefSeq, Jun 2010]

TFB1M (HGNC:17037): (transcription factor B1, mitochondrial) The protein encoded by this gene is a dimethyltransferase that methylates the conserved stem loop of mitochondrial 12S rRNA. The encoded protein also is part of the basal mitochondrial transcription complex and is necessary for mitochondrial gene expression. The methylation and transcriptional activities of this protein are independent of one another. Variations in this gene may influence the severity of aminoglycoside-induced deafness (AID).[provided by RefSeq, Aug 2010]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.884

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CLDN20	NM_001001346.3	c.239C>T	p.Ala80Val	missense_variant	2/2	ENST00000367165.3
TFB1M	NM_016020.4	c.666+9200G>A		intron_variant		ENST00000367166.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CLDN20	ENST00000367165.3	c.239C>T	p.Ala80Val	missense_variant	2/2	1	NM_001001346.3	P1
TFB1M	ENST00000367166.5	c.666+9200G>A		intron_variant		1	NM_016020.4	P1

Frequencies

GnomAD3 genomes AF: 0.000118 AC: 18 AN: 152146 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.000471

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000162

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000143 AC: 36 AN: 251392 Hom.: 0 AF XY: 0.000132 AC XY: 18 AN XY: 135866

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.000462

Gnomad NFE exome AF: 0.000220

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000144 AC: 210 AN: 1461892 Hom.: 0 Cov.: 38 AF XY: 0.000146 AC XY: 106 AN XY: 727248

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.000337

Gnomad4 NFE exome AF: 0.000165

Gnomad4 OTH exome AF: 0.000116

GnomAD4 genome AF: 0.000118 AC: 18 AN: 152146 Hom.: 0 Cov.: 32 AF XY: 0.000148 AC XY: 11 AN XY: 74316

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.000471

Gnomad4 NFE AF: 0.000162

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000169 Hom.: 0

Bravo AF: 0.000117

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.000233 AC: 2

ExAC AF: 0.000148 AC: 18

EpiCase AF: 0.000109

EpiControl AF: 0.000237

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 23, 2023

The c.239C>T (p.A80V) alteration is located in exon 2 (coding exon 1) of the CLDN20 gene. This alteration results from a C to T substitution at nucleotide position 239, causing the alanine (A) at amino acid position 80 to be replaced by a valine (V). 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	0.31
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Pathogenic	0.27
Cadd	Pathogenic	27
Dann	Pathogenic	1.0
DEOGEN2	Uncertain	0.62	D
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Benign	0.84	T
M_CAP	Pathogenic	0.29	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Pathogenic	0.83	D
MutationAssessor	Pathogenic	3.0	M
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.58	T
PROVEAN	Uncertain	-3.0	D
REVEL	Pathogenic	0.76
Sift	Uncertain	0.0030	D
Sift4G	Uncertain	0.014	D
Polyphen		1.0	D
Vest4		0.78
MVP		0.93
MPC		0.18
ClinPred		0.57	D
GERP RS		5.4
Varity_R		0.73
gMVP		0.74

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: rs141689255; hg19: chr6-155597092; COSMIC: COSV65696990;