X-154030726-G-C

Variant names:

• chrX-154030726-G-C
• rs781968415
• NM_001110792.2:c.1138C>G

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4 BS2

The NM_001110792.2(MECP2):​c.1138C>G​(p.His380Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000182 in 1,207,142 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 7 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000090 (0 hom., 1 hem., cov: 22)
  • Exomes 𝑓: 0.000019 (0 hom. 6 hem.)
• Consequence: MECP2 NM_001110792.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.28

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 Likely_benign. Variant got -5 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.288226).
• BS2: High Hemizygotes in GnomAdExome4 at 6 XL gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MECP2	NM_001110792.2	c.1138C>G	p.His380Asp	missense_variant	Exon 3 of 3	ENST00000453960.7	NP_001104262.1
MECP2	NM_004992.4	c.1102C>G	p.His368Asp	missense_variant	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.1138C>G	p.His380Asp	missense_variant	Exon 3 of 3	1	NM_001110792.2	ENSP00000395535.2
MECP2	ENST00000303391.11	c.1102C>G	p.His368Asp	missense_variant	Exon 4 of 4	1	NM_004992.4	ENSP00000301948.6

Frequencies

GnomAD3 genomes AF: 0.00000903 AC: 1 AN: 110683 Hom.: 0 Cov.: 22 AF XY: 0.0000304 AC XY: 1 AN XY: 32877

Gnomad AFR AF: 0.0000329

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: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.0000192 AC: 21 AN: 1096459 Hom.: 0 Cov.: 35 AF XY: 0.0000166 AC XY: 6 AN XY: 362141

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.0000238

Gnomad4 OTH exome AF: 0.0000217

GnomAD4 genome AF: 0.00000903 AC: 1 AN: 110683 Hom.: 0 Cov.: 22 AF XY: 0.0000304 AC XY: 1 AN XY: 32877

Gnomad4 AFR AF: 0.0000329

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Severe neonatal-onset encephalopathy with microcephaly Uncertain:1

Aug 24, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces histidine with aspartic acid at codon 368 of the MECP2 protein (p.His368Asp). The histidine residue is highly conserved and there is a moderate physicochemical difference between histidine and aspartic acid. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with MECP2-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.29
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.080
CADD	Benign	21
DANN	Uncertain	0.98
DEOGEN2	Benign	0.34	T;.
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.87	D;D
M_CAP	Pathogenic	0.40	D
MetaRNN	Benign	0.29	T;T
MetaSVM	Uncertain	-0.26	T
MutationAssessor	Benign	0.0	N;.
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	-1.1	N;N
REVEL	Uncertain	0.49
Sift	Benign	0.29	T;T
Sift4G	Benign	0.61	T;T
Polyphen		0.084	B;B
Vest4		0.40
MutPred		0.29		Gain of catalytic residue at H368 (P = 0.0439);.;
MVP		0.98
ClinPred		0.43	T
GERP RS		5.0
Varity_R		0.33
gMVP		0.71

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: rs781968415; hg19: chrX-153296177;