2-148178697-T-C

Variant names:

• chr2-148178697-T-C
• rs1293921044
• NM_001378120.1:c.-924-3T>C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Moderate BP6_Moderate

The NM_001378120.1(MBD5):​c.-924-3T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000126 in 398,232 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.000016 (0 hom.)
• Consequence: MBD5 NM_001378120.1 splice_region, intron
• Scores: Splicing: ADA: 0.0008191
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 0.554
• 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: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.38).
• BP6: Variant 2-148178697-T-C is Benign according to our data. Variant chr2-148178697-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 682419.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MBD5	NM_001378120.1	c.-924-3T>C		splice_region_variant, intron_variant	Intron 1 of 13	ENST00000642680.2	NP_001365049.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MBD5	ENST00000642680.2	c.-924-3T>C		splice_region_variant, intron_variant	Intron 1 of 13		NM_001378120.1	ENSP00000493871.2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152226 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.0000163 AC: 4 AN: 246006 Hom.: 0 Cov.: 0 AF XY: 0.0000160 AC XY: 2 AN XY: 124726

African (AFR) AF: 0.00 AC: 0 AN: 7156

American (AMR) AF: 0.00 AC: 0 AN: 7422

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 9208

East Asian (EAS) AF: 0.00 AC: 0 AN: 22706

South Asian (SAS) AF: 0.00 AC: 0 AN: 3016

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 21224

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 1284

European-Non Finnish (NFE) AF: 0.0000190 AC: 3 AN: 157656

Other (OTH) AF: 0.0000612 AC: 1 AN: 16334

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152226 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74380

African (AFR) AF: 0.00 AC: 0 AN: 41460

American (AMR) AF: 0.00 AC: 0 AN: 15292

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3464

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

South Asian (SAS) AF: 0.00 AC: 0 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68034

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Benign:1

May 02, 2018

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.38
CADD	Benign	11
DANN	Benign	0.86
PhyloP100		0.55
PromoterAI		0.016	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00082
dbscSNV1_RF	Benign	0.016
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

Other links and lift over

dbSNP: rs1293921044; hg19: chr2-148936266;