X-154031091-A-AAT

Position:

• chrX-154031091-A-AAT

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_001110792.2(MECP2):​c.772_773insAT​(p.Met258AsnfsTer3) variant causes a frameshift 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 Pathogenic (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: MECP2 NM_001110792.2 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 0.348

Genes affected

MECP2 (HGNC:6990): (methyl-CpG binding protein 2) DNA methylation is the major modification of eukaryotic genomes and plays an essential role in mammalian development. Human proteins MECP2, MBD1, MBD2, MBD3, and MBD4 comprise a family of nuclear proteins related by the presence in each of a methyl-CpG binding domain (MBD). Each of these proteins, with the exception of MBD3, is capable of binding specifically to methylated DNA. MECP2, MBD1 and MBD2 can also repress transcription from methylated gene promoters. In contrast to other MBD family members, MECP2 is X-linked and subject to X inactivation. MECP2 is dispensible in stem cells, but is essential for embryonic development. MECP2 gene mutations are the cause of most cases of Rett syndrome, a progressive neurologic developmental disorder and one of the most common causes of cognitive disability in females. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Oct 2015]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.484 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-154031091-A-AAT is Pathogenic according to our data. Variant chrX-154031091-A-AAT is described in ClinVar as [Pathogenic]. Clinvar id is 143672.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MECP2	NM_001110792.2	c.772_773insAT	p.Met258AsnfsTer3	frameshift_variant	3/3	ENST00000453960.7	NP_001104262.1
MECP2	NM_004992.4	c.736_737insAT	p.Met246AsnfsTer3	frameshift_variant	4/4	ENST00000303391.11	NP_004983.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MECP2	ENST00000303391.11	c.736_737insAT	p.Met246AsnfsTer3	frameshift_variant	4/4	1	NM_004992.4	ENSP00000301948	P1
MECP2	ENST00000453960.7	c.772_773insAT	p.Met258AsnfsTer3	frameshift_variant	3/3	1	NM_001110792.2	ENSP00000395535

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Rett syndrome Pathogenic:2

Pathogenic, no assertion criteria provided	curation	RettBASE	Sep 05, 2002	- -
Pathogenic, criteria provided, single submitter	curation	Centre for Population Genomics, CPG	Jan 12, 2024	This variant has been collected from RettBASE and curated to current modified ACMG/AMP criteria. Based on the classification scheme defined by the ClinGen Rett/Angelman-like Expert Panel for Rett/AS-like Disorders Specifications to the ACMG/AMP Variant Interpretation Guidelines VCEP 3.0, this variant is classified as pathogenic. At least the following criteria are met: Predicted to result in loss of function, and LOF is a known mechanism of disease (PVS1). Has been observed in at least 2 individuals with phenotypes consistent with MECP2-related disease (PS4_Supporting). This variant has been identified as a de novo occurrence in an individual with Rett syndrome without confirmation of paternity and maternity (PM6). This variant is absent from gnomAD (PM2_Supporting). -

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: rs61749749; hg19: chrX-153296542;