20-50958890-A-C

Position:

• chr20-50958890-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_014484.5(MOCS3):​c.48A>C​(p.Gln16His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000689 in 1,450,412 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 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)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: MOCS3 NM_014484.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.196

Genes affected

MOCS3 (HGNC:15765): (molybdenum cofactor synthesis 3) Molybdenum cofactor (MoCo) is necessary for the function of all molybdoenzymes. The protein encoded by this gene adenylates and activates molybdopterin synthase, an enzyme required for biosynthesis of MoCo. This gene contains no introns. A pseudogene of this gene is present on chromosome 14. [provided by RefSeq, Nov 2012]

DPM1 (HGNC:3005): (dolichyl-phosphate mannosyltransferase subunit 1, catalytic) Dolichol-phosphate mannose (Dol-P-Man) serves as a donor of mannosyl residues on the lumenal side of the endoplasmic reticulum (ER). Lack of Dol-P-Man results in defective surface expression of GPI-anchored proteins. Dol-P-Man is synthesized from GDP-mannose and dolichol-phosphate on the cytosolic side of the ER by the enzyme dolichyl-phosphate mannosyltransferase. Human DPM1 lacks a carboxy-terminal transmembrane domain and signal sequence and is regulated by DPM2. Mutations in this gene are associated with congenital disorder of glycosylation type Ie. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2015]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.07834554).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MOCS3	NM_014484.5	c.48A>C	p.Gln16His	missense_variant	1/1	ENST00000244051.3	NP_055299.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MOCS3	ENST00000244051.3	c.48A>C	p.Gln16His	missense_variant	1/1	6	NM_014484.5	ENSP00000244051.1
DPM1	ENST00000683466.1	c.-304T>G		5_prime_UTR_variant	1/8			ENSP00000507404.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000404 AC: 1 AN: 247350 Hom.: 0 AF XY: 0.00000743 AC XY: 1 AN XY: 134654

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000901

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.89e-7 AC: 1 AN: 1450412 Hom.: 0 Cov.: 32 AF XY: 0.00000139 AC XY: 1 AN XY: 718966

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.06e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

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

Mar 24, 2021

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with MOCS3-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamine with histidine at codon 16 of the MOCS3 protein (p.Gln16His). The glutamine residue is weakly conserved and there is a small physicochemical difference between glutamine and histidine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.15	T
BayesDel_noAF	Benign	-0.46
CADD	Benign	12
DANN	Benign	0.70
DEOGEN2	Benign	0.18	T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.065	N
LIST_S2	Benign	0.62	T
M_CAP	Benign	0.041	D
MetaRNN	Benign	0.078	T
MetaSVM	Benign	-0.98	T
MutationAssessor	Benign	1.3	L
PrimateAI	Benign	0.27	T
PROVEAN	Benign	-0.95	N
REVEL	Benign	0.13
Sift	Benign	0.070	T
Sift4G	Benign	0.065	T
Polyphen		0.0	B
Vest4		0.21
MutPred		0.14		Loss of solvent accessibility (P = 0.1077);
MVP		0.74
MPC		0.62
ClinPred		0.040	T
GERP RS		0.99
Varity_R		0.071
gMVP		0.29

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: rs771095371; hg19: chr20-49575427;