rs1557135251

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_001110792.2(MECP2):​c.1195_1246delCCCCCACCTCCACCTGAGCCCGAGAGCTCCGAGGACCCCACCAGCCCCCCTG​(p.Pro399SerfsTer5) variant causes a frameshift change. The variant allele was found at a frequency of 0.0000025 in 1,199,199 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 1 hemizygotes in GnomAD. It is difficult to determine the true allele frequency of this variant because it is of type DEL_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000095 ( 0 hom., 1 hem., cov: 16)
Exomes 𝑓: 0.0000018 ( 0 hom. 0 hem. )

Consequence

MECP2
NM_001110792.2 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 4.53

Publications

0 publications found
Variant links:
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]
MECP2 Gene-Disease associations (from GenCC):
  • chromosome Xq28 duplication syndrome
    Inheritance: XL Classification: DEFINITIVE Submitted by: G2P
  • Rett syndrome
    Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen, G2P
  • severe neonatal-onset encephalopathy with microcephaly
    Inheritance: XL Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
  • syndromic X-linked intellectual disability Lubs type
    Inheritance: XL Classification: DEFINITIVE Submitted by: G2P
  • atypical Rett syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • non-syndromic X-linked intellectual disability
    Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
  • X-linked intellectual disability-psychosis-macroorchidism syndrome
    Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
  • systemic lupus erythematosus
    Inheritance: Unknown Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 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. There are 137 pathogenic variants in the truncated region.
PP5
Variant X-154030617-TCAGGGGGGCTGGTGGGGTCCTCGGAGCTCTCGGGCTCAGGTGGAGGTGGGGG-T is Pathogenic according to our data. Variant chrX-154030617-TCAGGGGGGCTGGTGGGGTCCTCGGAGCTCTCGGGCTCAGGTGGAGGTGGGGG-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 189662.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MECP2NM_001110792.2 linkc.1195_1246delCCCCCACCTCCACCTGAGCCCGAGAGCTCCGAGGACCCCACCAGCCCCCCTG p.Pro399SerfsTer5 frameshift_variant Exon 3 of 3 ENST00000453960.7 NP_001104262.1
MECP2NM_004992.4 linkc.1159_1210delCCCCCACCTCCACCTGAGCCCGAGAGCTCCGAGGACCCCACCAGCCCCCCTG p.Pro387SerfsTer5 frameshift_variant Exon 4 of 4 ENST00000303391.11 NP_004983.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MECP2ENST00000453960.7 linkc.1195_1246delCCCCCACCTCCACCTGAGCCCGAGAGCTCCGAGGACCCCACCAGCCCCCCTG p.Pro399SerfsTer5 frameshift_variant Exon 3 of 3 1 NM_001110792.2 ENSP00000395535.2
MECP2ENST00000303391.11 linkc.1159_1210delCCCCCACCTCCACCTGAGCCCGAGAGCTCCGAGGACCCCACCAGCCCCCCTG p.Pro387SerfsTer5 frameshift_variant Exon 4 of 4 1 NM_004992.4 ENSP00000301948.6

Frequencies

GnomAD3 genomes
AF:
0.00000950
AC:
1
AN:
105316
Hom.:
0
Cov.:
16
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.000190
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000183
AC:
2
AN:
1093883
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
360941
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
26377
American (AMR)
AF:
0.00
AC:
0
AN:
35184
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
19370
East Asian (EAS)
AF:
0.00
AC:
0
AN:
30164
South Asian (SAS)
AF:
0.00
AC:
0
AN:
54123
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
37083
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
3985
European-Non Finnish (NFE)
AF:
0.00000238
AC:
2
AN:
841599
Other (OTH)
AF:
0.00
AC:
0
AN:
45998
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0296732), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000950
AC:
1
AN:
105316
Hom.:
0
Cov.:
16
AF XY:
0.0000348
AC XY:
1
AN XY:
28732
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
28397
American (AMR)
AF:
0.00
AC:
0
AN:
9795
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
2580
East Asian (EAS)
AF:
0.00
AC:
0
AN:
3384
South Asian (SAS)
AF:
0.00
AC:
0
AN:
2320
European-Finnish (FIN)
AF:
0.000190
AC:
1
AN:
5262
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
232
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
51286
Other (OTH)
AF:
0.00
AC:
0
AN:
1392

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Rett syndrome Pathogenic:1
Mar 15, 2024
Centre for Population Genomics, CPG
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:curation

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). This variant is absent from gnomAD (PM2_Supporting). Has been observed in at least 2 individuals with phenotypes consistent with MECP2-related disease (PS4_Supporting). ClinVar Variation ID: 189662,PMID 11283202. -

Severe neonatal-onset encephalopathy with microcephaly Pathogenic:1
Sep 08, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is also known as 1230del52. For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the MECP2 protein in which other variant(s) (p.Pro469Alafs*18) have been determined to be pathogenic (PMID: 32860008). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. ClinVar contains an entry for this variant (Variation ID: 189662). This premature translational stop signal has been observed in individual(s) with Angelman syndrome (PMID: 11283202). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Pro387Serfs*5) in the MECP2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 100 amino acid(s) of the MECP2 protein. -

Angelman syndrome Pathogenic:1
Apr 10, 2002
RettBASE
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:curation

- -

not provided Pathogenic:1
Aug 09, 2023
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Previously reported as c.1230del52 in a female patient with a clinical diagnosis of Angelman syndrome (Watson et al., 2001); Frameshift variant predicted to result in protein truncation in a gene for which loss-of-function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 11283202) -

Atypical Rett syndrome Pathogenic:1
Apr 01, 2001
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
4.5
Mutation Taster
=0/200
disease causing (ClinVar)

Splicing

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

Publications

Other links and lift over

dbSNP: rs1557135251; hg19: chrX-153296068; API