X-154097642-CGCGGCGGCG-CGCGGCGGCGGCG

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP6_Very_StrongBS2_Supporting

The NM_001110792.2(MECP2):​c.21_23dupCGC​(p.Ala8dup) variant causes a disruptive inframe insertion change. The variant allele was found at a frequency of 0.0002 in 1,024,821 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 36 hemizygotes in GnomAD. Variant has been reported in ClinVar as Benign (★★★).

Frequency

Genomes: 𝑓 0.00016 ( 0 hom., 2 hem., cov: 21)
Exomes 𝑓: 0.00020 ( 0 hom. 34 hem. )

Consequence

MECP2
NM_001110792.2 disruptive_inframe_insertion

Scores

Not classified

Clinical Significance

Benign reviewed by expert panel U:6B:7

Conservation

PhyloP100: 3.94
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]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -9 ACMG points.

BP6
Variant X-154097642-C-CGCG is Benign according to our data. Variant chrX-154097642-C-CGCG is described in ClinVar as [Benign]. Clinvar id is 93556.Status of the report is reviewed_by_expert_panel, 3 stars.
BS2
High Hemizygotes in GnomAd4 at 2 XL geneVariant has number of hemizygotes lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MECP2NM_001110792.2 linkc.21_23dupCGC p.Ala8dup disruptive_inframe_insertion Exon 1 of 3 ENST00000453960.7 NP_001104262.1 P51608-2A0A140VKC4Q59FJ6
MECP2NM_004992.4 linkc.-140_-138dupCGC 5_prime_UTR_variant Exon 1 of 4 ENST00000303391.11 NP_004983.1 P51608-1D3YJ43Q59FJ6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MECP2ENST00000453960.7 linkc.21_23dupCGC p.Ala8dup disruptive_inframe_insertion Exon 1 of 3 1 NM_001110792.2 ENSP00000395535.2 P51608-2
MECP2ENST00000303391.11 linkc.-140_-138dupCGC 5_prime_UTR_variant Exon 1 of 4 1 NM_004992.4 ENSP00000301948.6 P51608-1

Frequencies

GnomAD3 genomes
AF:
0.000160
AC:
17
AN:
106552
Hom.:
0
Cov.:
21
AF XY:
0.0000663
AC XY:
2
AN XY:
30188
show subpopulations
Gnomad AFR
AF:
0.0000337
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000307
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.000199
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000275
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000333
AC:
2
AN:
59976
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
15452
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000113
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.000181
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000205
AC:
188
AN:
918269
Hom.:
0
Cov.:
26
AF XY:
0.000119
AC XY:
34
AN XY:
284887
show subpopulations
Gnomad4 AFR exome
AF:
0.000202
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.000447
Gnomad4 SAS exome
AF:
0.0000944
Gnomad4 FIN exome
AF:
0.000139
Gnomad4 NFE exome
AF:
0.000214
Gnomad4 OTH exome
AF:
0.000190
GnomAD4 genome
AF:
0.000160
AC:
17
AN:
106552
Hom.:
0
Cov.:
21
AF XY:
0.0000663
AC XY:
2
AN XY:
30188
show subpopulations
Gnomad4 AFR
AF:
0.0000337
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.000307
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.000199
Gnomad4 NFE
AF:
0.000275
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.000151

ClinVar

Significance: Benign
Submissions summary: Uncertain:6Benign:7
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

not provided Uncertain:3Benign:2
Aug 20, 2013
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Oct 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

MECP2: BS2 -

-
Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Sep 23, 2013
GeneDx
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The c.23_24insCGC (aka c.21_23dupCGC) variant results in the duplication of a single Alanine residue in a poorly conserved region of the MECP2_e1 transcript. Although c.21_23dupCGC has not been published to our knowledge, it is reported in a gene specific mutation database as a variant of unknown pathogenicity. Additionally, a duplication of two Alanine residues in this region of the protein has been reported as a benign polymorphism because it was identified in a female with Rett syndrome and her unaffected mother in one family and did not co-segregate with intellectual disability in another family (Evans et al., 2005; Quenard et al., 2006). However, other variations in the number of Alanine or Glycine repeats in this region of the protein were found in approximately 1% of females with intellectual disability but a significantly smaller percentage of controls, so the authors suggested these variants may be associated with an increased risk for intellectual disability (Harvey et al., 2007). This variant has been observed to be inherited from an apparently unaffected mother. The variant is found in MECP2 panel(s). -

not specified Uncertain:3
Dec 10, 2020
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: MECP2 c.-140_-138dupCGC is located in the untranslated mRNA region upstream of the initiation codon in transcript NM_004992. The variant allele was found at a frequency of 3.3e-05 in 59976 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.-140_-138dupCGC in individuals affected with Rett Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Two other clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory cited the variant as benign and one laboratory cited the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Feb 03, 2006
RettBASE
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: curation

- -

Jun 01, 2015
Genetic Services Laboratory, University of Chicago
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Rett syndrome Benign:2
Feb 19, 2022
ClinGen Rett and Angelman-like Disorders Variant Curation Expert Panel
Significance: Benign
Review Status: reviewed by expert panel
Collection Method: curation

The allele frequency of the c.-140_-138dup variant in MECP2 (NM_004992.3) is over 0.01% in South Asian, European (non-Finnish), and Latino/Admixed american sub populations in gnomAD, which is high enough to meet the BS1 criteria based on thresholds defined by the ClinGen Rett/Angelman-like Expert Panel for Rett/AS-like conditions (BS1). The c.-140_-138dup variant in MECP2 is observed in at least 2 unaffected individuals (Invitae internal database) (BS2). The c.-140_-138dup variant is found in at least 3 patients with an alternate molecular basis of disease (Invitae internal database) (BP5). In summary the c.-140_-138dup variant in MECP2 is classified as a benign variant based on the ACMG/AMP criteria (BS1, BS2, BP5). -

Aug 14, 2023
Centre for Population Genomics, CPG
Significance: Benign
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 2.0, this variant is classified as benign. At least the following criteria are met: The allele frequency of this variant in at least one population in gnomAD v3 is higher than the 0.03% threshold defined by the ClinGen Rett/Angelman-like Expert Panel for Rett/AS-like Disorders VCEP 2.0 (BA1). -

Severe neonatal-onset encephalopathy with microcephaly Benign:1
Oct 30, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Inborn genetic diseases Benign:1
Jun 29, 2018
Ambry Genetics
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

MECP2-related disorder Benign:1
Dec 10, 2021
PreventionGenetics, part of Exact Sciences
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

Splicing

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs398123566; hg19: chrX-153363099; API