16-5071860-C-T

Variant summary

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

The NM_019109.5(ALG1):c.11C>T(p.Ser4Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000138 in 1,452,538 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. S4S) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: ALG1 NM_019109.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.858

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]

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=0.13094005).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALG1	NM_019109.5	c.11C>T	p.Ser4Leu	missense_variant	1/13	ENST00000262374.10
ALG1	XM_017023457.3	c.11C>T	p.Ser4Leu	missense_variant	1/12
ALG1	XR_007064892.1	n.18C>T		non_coding_transcript_exon_variant	1/10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALG1	ENST00000262374.10	c.11C>T	p.Ser4Leu	missense_variant	1/13	1	NM_019109.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000138 AC: 2 AN: 1452538 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 722752

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: 9.00e-7

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

ALG1-congenital disorder of glycosylation Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 15, 2022

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. This variant has not been reported in the literature in individuals affected with ALG1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces serine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 4 of the ALG1 protein (p.Ser4Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Benign	-0.043	T
BayesDel_noAF	Benign	-0.30
Cadd	Benign	13
Dann	Benign	0.87
DEOGEN2	Benign	0.054	T;T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.11	N
LIST_S2	Benign	0.51	T;T
M_CAP	Uncertain	0.11	D
MetaRNN	Benign	0.13	T;T
MetaSVM	Benign	-0.85	T
MutationAssessor	Benign	1.9	M;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-0.70	N;.
REVEL	Benign	0.14
Sift	Benign	0.41	T;.
Sift4G	Benign	0.24	T;T
Polyphen		0.012	B;.
Vest4		0.47
MutPred		0.41		Loss of disorder (P = 0.0039);Loss of disorder (P = 0.0039);
MVP		0.67
MPC		0.057
ClinPred		0.069	T
GERP RS		2.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.027
gMVP		0.59

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr16-5121861; COSMIC: COSV99275976; COSMIC: COSV99275976;