X-154031323-C-T

Variant names:

• chrX-154031323-C-T
• rs1603309480
• NM_001110792.2:c.541G>A
• MECP2 p.Glu181Lys

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1 PM2

The NM_001110792.2(MECP2):​c.541G>A​(p.Glu181Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000911 in 1,098,248 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E181G) has been classified as Uncertain significance. The gene MECP2 is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 9.1e-7 (0 hom. 0 hem.)
• Consequence: MECP2 NM_001110792.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.41
• 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: ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P, Orphanet
• 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: Uncertain_significance. The variant received 4 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 9 benign, 10 uncertain in NM_001110792.2
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001110792.2. 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.541G>A	p.Glu181Lys	missense	Exon 3 of 3	NP_001104262.1	A0A140VKC4
	MECP2	NM_004992.4	MANE Plus Clinical	c.505G>A	p.Glu169Lys	missense	Exon 4 of 4	NP_004983.1	D3YJ43
	MECP2	NM_001316337.2		c.226G>A	p.Glu76Lys	missense	Exon 5 of 5	NP_001303266.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MECP2	ENST00000453960.7	TSL:1 MANE Select	c.541G>A	p.Glu181Lys	missense	Exon 3 of 3	ENSP00000395535.2	P51608-2
	MECP2	ENST00000303391.11	TSL:1 MANE Plus Clinical	c.505G>A	p.Glu169Lys	missense	Exon 4 of 4	ENSP00000301948.6	P51608-1
	MECP2	ENST00000630151.3	TSL:5	c.505G>A	p.Glu169Lys	missense	Exon 4 of 4	ENSP00000486089.2	P51608-1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome AF: 9.11e-7 AC: 1 AN: 1098248 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 363602

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 26403

American (AMR) AF: 0.00 AC: 0 AN: 35207

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19386

East Asian (EAS) AF: 0.00 AC: 0 AN: 30206

South Asian (SAS) AF: 0.00 AC: 0 AN: 54148

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 40533

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4137

European-Non Finnish (NFE) AF: 0.00000119 AC: 1 AN: 842131

Other (OTH) AF: 0.00 AC: 0 AN: 46097

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 23

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.38	T
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.91	D
MetaRNN	Uncertain	0.60	D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Uncertain	2.3	M
PhyloP100		7.4
PrimateAI	Pathogenic	0.82	D
PROVEAN	Benign	-0.46	N
REVEL	Uncertain	0.52
Sift	Benign	0.049	D
Sift4G	Benign	0.26	T
Varity_R		0.48
gMVP		0.82
Mutation Taster		=46/54	disease causing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs1603309480;

hg19: chrX-153296774;