20-34393821-A-G

Position:

• chr20-34393821-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_031483.7(ITCH):​c.10A>G​(p.Ser4Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000123 in 1,461,362 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: ITCH NM_031483.7 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.51

Genes affected

ITCH (HGNC:13890): (itchy E3 ubiquitin protein ligase) This gene encodes a member of the Nedd4 family of HECT domain E3 ubiquitin ligases. HECT domain E3 ubiquitin ligases transfer ubiquitin from E2 ubiquitin-conjugating enzymes to protein substrates, thus targeting specific proteins for lysosomal degradation. The encoded protein plays a role in multiple cellular processes including erythroid and lymphoid cell differentiation and the regulation of immune responses. Mutations in this gene are a cause of syndromic multisystem autoimmune disease. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Mar 2012]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), ITCH. . Gene score misZ 3.5832 (greater than the threshold 3.09). Trascript score misZ 4.3516 (greater than threshold 3.09). GenCC has associacion of gene with syndromic multisystem autoimmune disease due to ITCH deficiency.
• BP4: Computational evidence support a benign effect (MetaRNN=0.08109656).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ITCH	NM_031483.7	c.10A>G	p.Ser4Gly	missense_variant	3/25	ENST00000374864.10	NP_113671.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ITCH	ENST00000374864.10	c.10A>G	p.Ser4Gly	missense_variant	3/25	1	NM_031483.7	ENSP00000363998	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000239 AC: 6 AN: 251462 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135904

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000217

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000123 AC: 18 AN: 1461362 Hom.: 0 Cov.: 30 AF XY: 0.0000110 AC XY: 8 AN XY: 727042

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000277

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.0000189

ExAC AF: 0.0000412 AC: 5

Asia WGS AF: 0.000866 AC: 3 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Syndromic multisystem autoimmune disease due to ITCH deficiency Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 09, 2020

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: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available"). This variant has not been reported in the literature in individuals with ITCH-related conditions. This variant is present in population databases (rs764016207, ExAC 0.03%). This sequence change replaces serine with glycine at codon 4 of the ITCH protein (p.Ser4Gly). The serine residue is moderately conserved and there is a small physicochemical difference between serine and glycine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.064
BayesDel_addAF	Benign	-0.44	T
BayesDel_noAF	Benign	-0.57
CADD	Benign	18
DANN	Benign	0.94
DEOGEN2	Benign	0.18	.;.;T
Eigen	Benign	-0.42
Eigen_PC	Benign	-0.23
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Benign	0.56	T;T;T
M_CAP	Benign	0.0084	T
MetaRNN	Benign	0.081	T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.0	N;.;N
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Benign	0.44	T
PROVEAN	Benign	-0.64	N;.;N
REVEL	Benign	0.12
Sift	Benign	0.14	T;.;T
Sift4G	Benign	0.30	T;.;T
Polyphen		0.0	.;.;B
Vest4		0.37
MVP		0.44
MPC		0.20
ClinPred		0.017	T
GERP RS		4.0
Varity_R		0.036
gMVP		0.24

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: rs764016207; hg19: chr20-32981627;