chr7-148807681-A-ACTT

Position:

• chr7-148807681-A-ACTT

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PM4_Supporting PP5_Moderate

The NM_004456.5(EZH2):​c.2220_2221insAAG​(p.Lys740dup) variant causes a inframe insertion change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 30)
• Consequence: EZH2 NM_004456.5 inframe_insertion
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.45

Genes affected

EZH2 (HGNC:3527): (enhancer of zeste 2 polycomb repressive complex 2 subunit) This gene encodes a member of the Polycomb-group (PcG) family. PcG family members form multimeric protein complexes, which are involved in maintaining the transcriptional repressive state of genes over successive cell generations. This protein associates with the embryonic ectoderm development protein, the VAV1 oncoprotein, and the X-linked nuclear protein. This protein may play a role in the hematopoietic and central nervous systems. Multiple alternatively splcied transcript variants encoding distinct isoforms have been identified for this gene. [provided by RefSeq, Feb 2011]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 2 uncertain in NM_004456.5
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_004456.5. Strenght limited to Supporting due to length of the change: 1aa.
• PP5: Variant 7-148807681-A-ACTT is Pathogenic according to our data. Variant chr7-148807681-A-ACTT is described in ClinVar as [Likely_pathogenic]. Clinvar id is 577229.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
EZH2	NM_004456.5	c.2220_2221insAAG	p.Lys740dup	inframe_insertion	20/20	ENST00000320356.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
EZH2	ENST00000320356.7	c.2220_2221insAAG	p.Lys740dup	inframe_insertion	20/20	1	NM_004456.5	P4

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 30

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Weaver syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 09, 2018

This variant, c.2218_2220dupAAG, results in the insertion of 1 amino acid(s) to the EZH2 protein (p.Lys740dup), but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (ExAC no frequency). This variant has been observed to be de novo in an individual affected with overgrowth, developmental delay and advanced bone age (Invitae). Experimental studies and prediction algorithms are not available for this variant, and the functional significance of the duplicated amino acid is currently unknown. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1563181659; hg19: chr7-148504773;