20-50958896-G-A

Variant names:

• chr20-50958896-G-A
• rs1421205759
• NM_014484.5:c.54G>A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_014484.5(MOCS3):​c.54G>A​(p.Glu18Glu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000757 in 1,452,192 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000076 (0 hom.)
• Consequence: MOCS3 NM_014484.5 synonymous
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.22

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 Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.51).
• BP7: Synonymous conserved (PhyloP=1.22 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MOCS3	NM_014484.5	c.54G>A	p.Glu18Glu	synonymous_variant	Exon 1 of 1	ENST00000244051.3	NP_055299.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MOCS3	ENST00000244051.3	c.54G>A	p.Glu18Glu	synonymous_variant	Exon 1 of 1	6	NM_014484.5	ENSP00000244051.1
DPM1	ENST00000683466.1	c.-310C>T		5_prime_UTR_variant	Exon 1 of 8			ENSP00000507404.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000757 AC: 11 AN: 1452192 Hom.: 0 Cov.: 32 AF XY: 0.00000555 AC XY: 4 AN XY: 720238

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: 0.00000996

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000565 Hom.: 0

Bravo AF: 0.00000378

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Dec 12, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects codon 18 of the MOCS3 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the MOCS3 protein. This variant is present in population databases (no rsID available, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with MOCS3-related conditions. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.51
CADD	Benign	9.7
DANN	Benign	0.75
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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: rs1421205759; hg19: chr20-49575433;