chr21-46235363-G-C

Position:

• chr21-46235363-G-C

Variant summary

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

The NM_003906.5(MCM3AP):​c.5848C>G​(p.Leu1950Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: MCM3AP NM_003906.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.34

Genes affected

MCM3AP (HGNC:6946): (minichromosome maintenance complex component 3 associated protein) The minichromosome maintenance protein 3 (MCM3) is one of the MCM proteins essential for the initiation of DNA replication. The protein encoded by this gene is a MCM3 binding protein. It was reported to have phosphorylation-dependent DNA-primase activity, which was up-regulated in antigen immunization induced germinal center. This protein was demonstrated to be an acetyltransferase that acetylates MCM3 and plays a role in DNA replication. The mutagenesis of a nuclear localization signal of MCM3 affects the binding of this protein with MCM3, suggesting that this protein may also facilitate MCM3 nuclear localization. This gene is expressed in the brain or in neuronal tissue. An allelic variant encoding amino acid Lys at 915, instead of conserved Glu, has been identified in patients with mild intellectual disability. [provided by RefSeq, Jan 2014]

MCM3AP-AS1 (HGNC:16417): (MCM3AP antisense RNA 1)

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=0.39628917).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MCM3AP	NM_003906.5	c.5848C>G	p.Leu1950Val	missense_variant	28/28	ENST00000291688.6	NP_003897.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MCM3AP	ENST00000291688.6	c.5848C>G	p.Leu1950Val	missense_variant	28/28	1	NM_003906.5	ENSP00000291688.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 22, 2023

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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant  is likely to be tolerated. This variant has not been reported in the literature in individuals affected with MCM3AP-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces leucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1950 of the MCM3AP protein (p.Leu1950Val). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Benign	-0.10	T
BayesDel_noAF	Benign	-0.38
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Benign	0.26	T;T
Eigen	Uncertain	0.29
Eigen_PC	Uncertain	0.23
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.79	T;.
M_CAP	Benign	0.017	T
MetaRNN	Benign	0.40	T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.7	M;M
PrimateAI	Benign	0.39	T
PROVEAN	Benign	-1.3	N;N
REVEL	Benign	0.12
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.015	D;D
Polyphen		1.0	D;D
Vest4		0.42
MutPred		0.29		Gain of MoRF binding (P = 0.073);Gain of MoRF binding (P = 0.073);
MVP		0.36
MPC		0.19
ClinPred		0.91	D
GERP RS		4.0
Varity_R		0.33
gMVP		0.46

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: rs2080501085; hg19: chr21-47655277;