chrX-154030643-GCTCTCGGGCTCAGGTGGAGGT-G

Variant names:

• chrX-154030643-GCTCTCGGGCTCAGGTGGAGGT-G
• rs1557135539
• NM_001110792.2:c.1200_1220delACCTCCACCTGAGCCCGAGAG

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1 PM4

The NM_001110792.2(MECP2):​c.1200_1220delACCTCCACCTGAGCCCGAGAG​(p.Pro401_Ser407del) variant causes a disruptive inframe deletion change. 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 Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. P400P) has been classified as Benign.

• Frequency: Genomes: not found (cov: 16)
• Consequence: MECP2 NM_001110792.2 disruptive_inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.37
• Publications: 0 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 13 benign, 12 uncertain in NM_001110792.2
• PM4: Nonframeshift variant in NON repetitive region in NM_001110792.2.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MECP2	NM_001110792.2	c.1200_1220delACCTCCACCTGAGCCCGAGAG	p.Pro401_Ser407del	disruptive_inframe_deletion	Exon 3 of 3	ENST00000453960.7	NP_001104262.1
MECP2	NM_004992.4	c.1164_1184delACCTCCACCTGAGCCCGAGAG	p.Pro389_Ser395del	disruptive_inframe_deletion	Exon 4 of 4	ENST00000303391.11	NP_004983.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MECP2	ENST00000453960.7	c.1200_1220delACCTCCACCTGAGCCCGAGAG	p.Pro401_Ser407del	disruptive_inframe_deletion	Exon 3 of 3	1	NM_001110792.2	ENSP00000395535.2
MECP2	ENST00000303391.11	c.1164_1184delACCTCCACCTGAGCCCGAGAG	p.Pro389_Ser395del	disruptive_inframe_deletion	Exon 4 of 4	1	NM_004992.4	ENSP00000301948.6

Frequencies

GnomAD3 genomes Cov.: 16

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 16

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Severe neonatal-onset encephalopathy with microcephaly Uncertain:1

Oct 30, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Experimental studies and prediction algorithms are not available for this variant, and the functional significance of the deleted amino acids is currently unknown. This variant, c.1164_1184delACCTCCACCTGAGCCCGAGAG, results in the deletion of 7 amino acids of the MECP2 protein (p.Pro389_Ser395del), but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with MECP2-related disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		5.4

Splicing

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

Other links and lift over

dbSNP: rs1557135539; hg19: chrX-153296094;