2-196217055-C-T

Variant names:

• chr2-196217055-C-T
• NM_001348768.2:c.4447G>A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_001348768.2(HECW2):​c.4447G>A​(p.Ala1483Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: HECW2 NM_001348768.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.50

Genes affected

HECW2 (HGNC:29853): (HECT, C2 and WW domain containing E3 ubiquitin protein ligase 2) This gene encodes a member of a family of E3 ubiquitin ligases which plays an important role in the proliferation, migration and differentiation of neural crest cells as a regulator of glial cell line-derived neurotrophic factor (GDNF)/Ret signaling. This gene also plays an important role in angiogenesis through stabilization of endothelial cell-to-cell junctions as a regulator of angiomotin-like 1 stability. The encoded protein contains an N-terminal calcium/lipid-binding (C2) domain involved in membrane targeting, two-four WW domains responsible for cellular localization and substrate recognition, and a C-terminal homologous with E6-associated protein C-terminus (HECT) catalytic domain. Naturally occurring mutations in this gene are associated with neurodevelopmental delay, hypotonia, and epilepsy. The decreased expression of this gene in the aganglionic colon is associated with Hirschsprung's disease. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the HECW2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 31 curated pathogenic missense variants (we use a threshold of 10). The gene has 62 curated benign missense variants. Gene score misZ: 3.3052 (above the threshold of 3.09). Trascript score misZ: 3.6429 (above the threshold of 3.09). GenCC associations: The gene is linked to neurodevelopmental disorder with hypotonia, seizures, and absent language, complex neurodevelopmental disorder.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HECW2	NM_001348768.2	c.4447G>A	p.Ala1483Thr	missense_variant	Exon 27 of 29	ENST00000644978.2	NP_001335697.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HECW2	ENST00000644978.2	c.4447G>A	p.Ala1483Thr	missense_variant	Exon 27 of 29		NM_001348768.2	ENSP00000495418.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Sep 29, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.4447G>A (p.A1483T) alteration is located in exon 27 (coding exon 26) of the HECW2 gene. This alteration results from a G to A substitution at nucleotide position 4447, causing the alanine (A) at amino acid position 1483 to be replaced by a threonine (T). 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	0.17
BayesDel_addAF	Benign	-0.038	T
BayesDel_noAF	Benign	-0.29
CADD	Uncertain	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.060	T;.;T;T
Eigen	Uncertain	0.47
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	.;D;.;D
M_CAP	Benign	0.0093	T
MetaRNN	Uncertain	0.45	T;T;T;T
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	0.43	N;.;N;N
PrimateAI	Pathogenic	0.80	T
PROVEAN	Benign	-2.0	N;.;.;.
REVEL	Benign	0.15
Sift	Benign	0.037	D;.;.;.
Sift4G	Benign	0.17	T;.;.;.
Polyphen		0.90	P;.;P;P
Vest4		0.49
MutPred		0.49		Gain of MoRF binding (P = 0.1055);.;Gain of MoRF binding (P = 0.1055);Gain of MoRF binding (P = 0.1055);
MVP		0.33
MPC		1.0
ClinPred		0.88	D
GERP RS		5.1
Varity_R		0.27
gMVP		0.62

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-197081779;