rs1060501150

chr2-148470221-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_001378120.1(MBD5):c.2278C>T(p.His760Tyr) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. H760R) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MBD5 NM_001378120.1 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.46

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3620327).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MBD5	NM_001378120.1	c.2278C>T	p.His760Tyr	missense_variant	8/14	ENST00000642680.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MBD5	ENST00000642680.2	c.2278C>T	p.His760Tyr	missense_variant	8/14		NM_001378120.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 12, 2016

This sequence change replaces histidine with tyrosine at codon 760 of the MBD5 protein (p.His760Tyr). The histidine residue is highly conserved and there is a moderate physicochemical difference between histidine and tyrosine. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a MBD5-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C65"). In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Uncertain	0.016	T
BayesDel_noAF	Benign	-0.22
Cadd	Uncertain	23
Dann	Uncertain	0.99
DEOGEN2	Benign	0.061	T;.;.;.;T
Eigen	Uncertain	0.27
Eigen_PC	Uncertain	0.38
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.88	D;.;D;D;D
M_CAP	Benign	0.0054	T
MetaRNN	Benign	0.36	T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.8	L;.;.;L;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.62	T
PROVEAN	Benign	-1.3	N;.;.;.;N
REVEL	Benign	0.097
Sift	Uncertain	0.0050	D;.;.;.;D
Sift4G	Benign	0.84	T;.;.;T;T
Polyphen		0.81	P;.;.;P;.
Vest4		0.68
MutPred		0.40		Loss of disorder (P = 0.036);Loss of disorder (P = 0.036);Loss of disorder (P = 0.036);Loss of disorder (P = 0.036);Loss of disorder (P = 0.036);
MVP		0.20
MPC		0.30
ClinPred		0.82	D
GERP RS		5.0
Varity_R		0.33
gMVP		0.58

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: rs1060501150; hg19: chr2-149227790;