2-148489423-G-C

Variant names:

• chr2-148489423-G-C
• rs1553520435
• NM_001378120.1:c.3791G>C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001378120.1(MBD5):​c.3791G>C​(p.Arg1264Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,866 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1264I) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MBD5 NM_001378120.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.34
• Publications: 0 publications found

Genes affected

MBD5 (HGNC:20444): (methyl-CpG binding domain protein 5) This gene encodes a member of the methyl-CpG-binding domain (MBD) family. The MBD consists of about 70 residues and is the minimal region required for a methyl-CpG-binding protein binding specifically to methylated DNA. In addition to the MBD domain, this protein contains a PWWP domain (Pro-Trp-Trp-Pro motif), which consists of 100-150 amino acids and is found in numerous proteins that are involved in cell division, growth and differentiation. Mutations in this gene cause an autosomal dominant type of cognitive disability. The encoded protein interacts with the polycomb repressive complex PR-DUB which catalyzes the deubiquitination of a lysine residue of histone 2A. Haploinsufficiency of this gene is associated with a syndrome involving microcephaly, intellectual disabilities, severe speech impairment, and seizures. Alternatively spliced transcript variants have been found, but their full-length nature is not determined. [provided by RefSeq, Jul 2017]

MBD5 Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• intellectual disability, autosomal dominant 1

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• autosomal dominant non-syndromic intellectual disability

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2155689).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MBD5	NM_001378120.1	c.3791G>C	p.Arg1264Thr	missense_variant	Exon 11 of 14	ENST00000642680.2	NP_001365049.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MBD5	ENST00000642680.2	c.3791G>C	p.Arg1264Thr	missense_variant	Exon 11 of 14		NM_001378120.1	ENSP00000493871.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461866 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727234

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112002

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Intellectual disability, autosomal dominant 1 Uncertain:1

Sep 07, 2022

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Not Available"; Align-GVGD: "Class C25"). This variant has not been reported in the literature in individuals affected with MBD5-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with threonine, which is neutral and polar, at codon 1031 of the MBD5 protein (p.Arg1031Thr). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Uncertain	0.029	T
BayesDel_noAF	Benign	-0.20
CADD	Uncertain	24
DANN	Benign	0.93
DEOGEN2	Benign	0.030	T;.;.;T
Eigen	Uncertain	0.42
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.91	D;.;D;D
M_CAP	Benign	0.0055	T
MetaRNN	Benign	0.22	T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.69	N;.;.;.
PhyloP100		5.3
PrimateAI	Uncertain	0.62	T
PROVEAN	Benign	-0.060	N;.;.;N
REVEL	Benign	0.17
Sift	Uncertain	0.0050	D;.;.;D
Sift4G	Benign	0.39	T;.;.;T
Polyphen		0.88	P;.;.;D
Vest4		0.81
MutPred		0.27		.;.;.;Gain of glycosylation at R1264 (P = 0.0279);
MVP		0.27
MPC		0.23
ClinPred		0.46	T
GERP RS		5.9
Varity_R		0.19
gMVP		0.29
Mutation Taster		=85/15	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs1553520435; hg19: chr2-149246992;