X-154031427-G-C

Variant names:

• chrX-154031427-G-C
• rs61748390
• NM_001110792.2:c.437C>G

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PS3 PM2 PP3_Strong PP5_Very_Strong

The NM_001386137.1(MECP2):​c.-160C>G variant causes a 5 prime UTR premature start codon gain change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV001362253: "In functional studies, the variant has been reported to reduce the ability of the MECP2 protein to bind and cluster heterochromatin and was shown to cause destabilization of the methyl-CpG-binding domain of the protein (example: Agarwal_2011, Kucukkal_2015)."" and additional evidence is available in ClinVar. The gene MECP2 is included in the ClinGen Criteria Specification Registry.

• Frequency: Genomes: not found (cov: 23)
• Consequence: MECP2 NM_001386137.1 5_prime_UTR_premature_start_codon_gain
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:20
• Conservation: PhyloP100: 9.46
• Publications: 25 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: Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics, Orphanet, 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

Specifications for MECP2 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV001362253: "In functional studies, the variant has been reported to reduce the ability of the MECP2 protein to bind and cluster heterochromatin and was shown to cause destabilization of the methyl-CpG-binding domain of the protein (example: Agarwal_2011, Kucukkal_2015)."; SCV002506805: Functional studies have suggested that the c.401C>G (p.Ser134Cys) variant destabilizes the MBD domain of the MECP2 protein and reduces its ability to bind and cluster heterochromatin [PMID: 26418480; PMID: 21831886].; SCV000329817: Published functional studies suggest reduced ability of the MECP2 protein to bind and cluster heterochromatin (PMID: 21831886, 26418480); SCV000827093: Experimental studies have shown that this missense change affects MECP2 function (PMID: 26418480).; SCV002625532: In one functional study using mouse myoblasts, authors show that this mutation significantly decreased chromocenter clustering compared to wildtype indicating a reduction in the ability of this variant to bind heterochromatin (Agarwal, 2011).; SCV005350497: Functional studies have demonstrated this variant impacts the ability of MECP2 to interact with heterochromatin (Kucukkal et al. 2015. PubMed ID: 26418480).
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant X-154031427-G-C is Pathogenic according to our data. Variant chrX-154031427-G-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 143562.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001386137.1. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MECP2	NM_001110792.2	MANE Select	c.437C>G	p.Ser146Cys	missense	Exon 3 of 3	NP_001104262.1	A0A140VKC4
	MECP2	NM_004992.4	MANE Plus Clinical	c.401C>G	p.Ser134Cys	missense	Exon 4 of 4	NP_004983.1	D3YJ43
	MECP2	NM_001386137.1		c.-160C>G		5_prime_UTR_premature_start_codon_gain	Exon 5 of 6	NP_001373066.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MECP2	ENST00000453960.7	TSL:1 MANE Select	c.437C>G	p.Ser146Cys	missense	Exon 3 of 3	ENSP00000395535.2	P51608-2
	MECP2	ENST00000303391.11	TSL:1 MANE Plus Clinical	c.401C>G	p.Ser134Cys	missense	Exon 4 of 4	ENSP00000301948.6	P51608-1
	MECP2	ENST00000630151.3	TSL:5	c.401C>G	p.Ser134Cys	missense	Exon 4 of 4	ENSP00000486089.2	P51608-1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 23

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
11	-	-	Rett syndrome (11)
5	-	-	not provided (5)
1	-	-	Inborn genetic diseases (1)
1	-	-	MECP2-related disorder (1)
1	-	-	Rett syndrome;C0796222:X-linked intellectual disability-psychosis-macroorchidism syndrome;C1845336:Autism, susceptibility to, X-linked 3;C1846058:Syndromic X-linked intellectual disability Lubs type;C1968556:Severe neonatal-onset encephalopathy with microcephaly (1)
1	-	-	Severe neonatal-onset encephalopathy with microcephaly (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.73	D
BayesDel_noAF	Pathogenic	0.81
CADD	Uncertain	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	1.0	D
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.2	M
PhyloP100		9.5
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-5.0	D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0090	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.95		Gain of methylation at K135 (P = 0.0153)
MVP		1.0
ClinPred		1.0	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.97
gMVP		0.99
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs61748390; hg19: chrX-153296878;