9-70126293-G-A

Variant names:

• chr9-70126293-G-A
• rs748587421
• NM_153267.5:c.778G>A

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP6_Moderate

The NM_153267.5(MAMDC2):​c.778G>A​(p.Val260Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,614,056 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: MAMDC2 NM_153267.5 missense
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 0.339
• Publications: 0 publications found

Genes affected

MAMDC2 (HGNC:23673): (MAM domain containing 2) Predicted to enable glycosaminoglycan binding activity. Predicted to act upstream of or within peptide cross-linking via chondroitin 4-sulfate glycosaminoglycan. Located in endoplasmic reticulum. [provided by Alliance of Genome Resources, Apr 2022]

MAMDC2-AS1 (HGNC:48719): (MAMDC2 antisense RNA 1)

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.04274878).
• BP6: Variant 9-70126293-G-A is Benign according to our data. Variant chr9-70126293-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 4050741.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MAMDC2	NM_153267.5	c.778G>A	p.Val260Ile	missense_variant	Exon 6 of 14	ENST00000377182.5	NP_694999.3
MAMDC2	NM_001347990.2	c.778G>A	p.Val260Ile	missense_variant	Exon 6 of 12		NP_001334919.1
MAMDC2	NR_125850.1	n.1395G>A		non_coding_transcript_exon_variant	Exon 6 of 14

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MAMDC2	ENST00000377182.5	c.778G>A	p.Val260Ile	missense_variant	Exon 6 of 14	1	NM_153267.5	ENSP00000366387.4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152178 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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: 0.0000119 AC: 3 AN: 251198 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461878 Hom.: 0 Cov.: 43 AF XY: 0.00000550 AC XY: 4 AN XY: 727238

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

American (AMR) AF: 0.000112 AC: 5 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1112000

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

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152178 Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1 AN XY: 74338

African (AFR) AF: 0.00 AC: 0 AN: 41448

American (AMR) AF: 0.0000655 AC: 1 AN: 15278

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5188

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68036

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

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000189

ExAC AF: 0.0000247 AC: 3

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Benign:1

Jun 03, 2025

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.067
BayesDel_addAF	Benign	-0.50	T
BayesDel_noAF	Benign	-0.77
CADD	Benign	7.6
DANN	Benign	0.70
DEOGEN2	Benign	0.0032	T
Eigen	Benign	-0.93
Eigen_PC	Benign	-0.81
FATHMM_MKL	Benign	0.61	D
LIST_S2	Benign	0.59	T
M_CAP	Benign	0.0041	T
MetaRNN	Benign	0.043	T
MetaSVM	Benign	-0.91	T
MutationAssessor	Benign	0.63	N
PhyloP100		0.34
PrimateAI	Benign	0.24	T
PROVEAN	Benign	-0.19	N
REVEL	Benign	0.036
Sift	Benign	0.50	T
Sift4G	Benign	0.45	T
Polyphen		0.0	B
Vest4		0.035
MutPred		0.45		Gain of sheet (P = 0.0827);
MVP		0.13
MPC		0.095
ClinPred		0.012	T
GERP RS		1.4
Varity_R		0.021
gMVP		0.15
Mutation Taster		=92/8	polymorphism

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

Other links and lift over

dbSNP: rs748587421; hg19: chr9-72741209;