rs201649831

Variant names:

• chr2-148483111-C-T
• rs201649831
• NM_001378120.1:c.2520C>T

Variant summary

Our verdict is Benign. The variant received -15 ACMG points: 0P and 15B. BP4_Strong BP6_Moderate BP7 BS1 BS2

The NM_001378120.1(MBD5):​c.2520C>T​(p.Gly840Gly) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000368 in 1,603,438 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 0.0000067 (0 hom., cov: 31)
  • Exomes 𝑓: 0.000040 (0 hom.)
• Consequence: MBD5 NM_001378120.1 splice_region, synonymous
• Scores: Splicing: ADA: 0.00001223
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -0.643
• 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: Benign. The variant received -15 ACMG points.

• BP4: Computational evidence support a benign effect (REVEL=0.006).
• BP6: Variant 2-148483111-C-T is Benign according to our data. Variant chr2-148483111-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 536682.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-0.643 with no splicing effect.
• BS1: Variant frequency is greater than expected in population nfe. GnomAdExome4 allele frequency = 0.0000399 (58/1455182) while in subpopulation NFE AF = 0.0000504 (56/1110824). AF 95% confidence interval is 0.0000398. There are 0 homozygotes in GnomAdExome4. There are 25 alleles in the male GnomAdExome4 subpopulation. Median coverage is 34. This position passed quality control check.
• BS2: High AC in GnomAdExome4 at 58 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MBD5	NM_001378120.1	c.2520C>T	p.Gly840Gly	splice_region_variant, synonymous_variant	Exon 9 of 14	ENST00000642680.2	NP_001365049.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MBD5	ENST00000642680.2	c.2520C>T	p.Gly840Gly	splice_region_variant, synonymous_variant	Exon 9 of 14		NM_001378120.1	ENSP00000493871.2

Frequencies

GnomAD3 genomes AF: 0.00000675 AC: 1 AN: 148256 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000250

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

GnomAD2 exomes AF: 0.00000813 AC: 2 AN: 245890 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000180

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000399 AC: 58 AN: 1455182 Hom.: 0 Cov.: 34 AF XY: 0.0000345 AC XY: 25 AN XY: 724068

African (AFR) AF: 0.0000302 AC: 1 AN: 33166

American (AMR) AF: 0.00 AC: 0 AN: 44268

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26002

East Asian (EAS) AF: 0.00 AC: 0 AN: 39640

South Asian (SAS) AF: 0.00 AC: 0 AN: 85778

European-Finnish (FIN) AF: 0.0000202 AC: 1 AN: 49566

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5740

European-Non Finnish (NFE) AF: 0.0000504 AC: 56 AN: 1110824

Other (OTH) AF: 0.00 AC: 0 AN: 60198

GnomAD4 genome AF: 0.00000675 AC: 1 AN: 148256 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 72010

African (AFR) AF: 0.0000250 AC: 1 AN: 39978

American (AMR) AF: 0.00 AC: 0 AN: 14832

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3458

East Asian (EAS) AF: 0.00 AC: 0 AN: 5122

South Asian (SAS) AF: 0.00 AC: 0 AN: 4730

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 9538

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 310

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67338

Other (OTH) AF: 0.00 AC: 0 AN: 2046

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

Intellectual disability, autosomal dominant 1 Benign:1

Jul 01, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
CADD	Benign	0.47
DANN	Benign	0.57
PhyloP100		-0.64
Mutation Taster		=68/32	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000012
dbscSNV1_RF	Benign	0.0020
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: rs201649831; hg19: chr2-149240680;