rs782027467

Positions:

• chrX-154031093-G-C

Variant summary

Our verdict is Benign. Variant got -17 ACMG points: 0P and 17B. BP4_Strong BP6_Very_Strong BP7 BS2

The NM_001110792.2(MECP2):​c.771C>G​(p.Val257Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000031 in 1,098,212 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 10 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 0.000031 (0 hom. 10 hem.)
• Consequence: MECP2 NM_001110792.2 synonymous
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:5
• Conservation: PhyloP100: 0.584

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 Benign. Variant got -17 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.51).
• BP6: Variant X-154031093-G-C is Benign according to our data. Variant chrX-154031093-G-C is described in ClinVar as [Likely_benign]. Clinvar id is 413770.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.584 with no splicing effect.
• BS2: High Hemizygotes in GnomAdExome4 at 10 XL gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MECP2	NM_001110792.2	c.771C>G	p.Val257Val	synonymous_variant	3/3	ENST00000453960.7	NP_001104262.1
MECP2	NM_004992.4	c.735C>G	p.Val245Val	synonymous_variant	4/4	ENST00000303391.11	NP_004983.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MECP2	ENST00000453960.7	c.771C>G	p.Val257Val	synonymous_variant	3/3	1	NM_001110792.2	ENSP00000395535.2
MECP2	ENST00000303391.11	c.735C>G	p.Val245Val	synonymous_variant	4/4	1	NM_004992.4	ENSP00000301948.6

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD3 exomes AF: 0.000131 AC: 24 AN: 183217 Hom.: 0 AF XY: 0.0000886 AC XY: 6 AN XY: 67745

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000875

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000310 AC: 34 AN: 1098212 Hom.: 0 Cov.: 36 AF XY: 0.0000275 AC XY: 10 AN XY: 363572

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000653

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000131

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 23

Alfa AF: 0.0000434 Hom.: 0

Bravo AF: 0.0000491

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Severe neonatal-onset encephalopathy with microcephaly Benign:1

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 12, 2023

- -

not specified Benign:1

Benign, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Sep 04, 2018

Variant summary: MECP2 c.735C>G alters a conserved nucleotide resulting in a synonymous change. Several computational tools predict a significant impact on normal splicing: five predict the variant strengthens a cryptic 5 prime donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00013 in 178616 control chromosomes, predominantly within the Latino subpopulation at a frequency of 0.00087 in the gnomAD database. This frequency within Latino control individuals is approximately 104-fold above the estimated maximal expected allele frequency for a pathogenic variant in MECP2 causing Rett Syndrome phenotype (8.3e-06), strongly suggesting that the variant is a benign polymorphism found primarily in populations of Latino origin. To our knowledge, no occurrence of c.735C>G in individuals affected with Rett Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as benign. Based on the evidence outlined above, the variant was classified as benign. -

Inborn genetic diseases Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 31, 2018

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. -

not provided Benign:1

Benign, criteria provided, single submitter

clinical testing

GeneDx

Nov 30, 2018

- -

MECP2-related disorder Benign:1

Likely benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Jan 03, 2022

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
BayesDel_noAF	Benign	-0.51
CADD	Benign	6.5
DANN	Benign	0.65
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.6

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs782027467; hg19: chrX-153296544;