chr16-5078856-G-A

Variant names:

• chr16-5078856-G-A
• rs12921879
• NM_019109.5:c.840G>A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_019109.5(ALG1):​c.840G>A​(p.Leu280Leu) variant causes a synonymous 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. L280L) has been classified as Benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: ALG1 NM_019109.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.802
• Publications: 6 publications found

Genes affected

ALG1 (HGNC:18294): (ALG1 chitobiosyldiphosphodolichol beta-mannosyltransferase) The enzyme encoded by this gene catalyzes the first mannosylation step in the biosynthesis of lipid-linked oligosaccharides. This gene is mutated in congenital disorder of glycosylation type Ik. [provided by RefSeq, Dec 2008]

ALG1 Gene-Disease associations (from GenCC):

• ALG1-congenital disorder of glycosylation

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, G2P, Orphanet, Labcorp Genetics (formerly Invitae), PanelApp Australia

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.47).
• BP7: Synonymous conserved (PhyloP=0.802 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALG1	NM_019109.5	c.840G>A	p.Leu280Leu	synonymous_variant	Exon 7 of 13	ENST00000262374.10	NP_061982.3
ALG1	NM_001438123.1	c.840G>A	p.Leu280Leu	synonymous_variant	Exon 7 of 12		NP_001425052.1
ALG1	NM_001330504.2	c.507G>A	p.Leu169Leu	synonymous_variant	Exon 7 of 13		NP_001317433.1
ALG1	XR_007064892.1	n.847G>A		non_coding_transcript_exon_variant	Exon 7 of 10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ALG1	ENST00000262374.10	c.840G>A	p.Leu280Leu	synonymous_variant	Exon 7 of 13	1	NM_019109.5	ENSP00000262374.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 62

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 61

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.47
CADD	Benign	9.2
DANN	Benign	0.85
PhyloP100		0.80
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs12921879; hg19: chr16-5128857;