dbSNP rs2060527471: ALG12:p.Ter489Cysext*? (chr22-49903838-T-G) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PM4

The NM_024105.4(ALG12):c.1467A>C(p.Ter489Cysext*?) variant causes a stop lost change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,820 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 (★). Synonymous variant affecting the same amino acid position (i.e. *489*) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

ALG12
NM_024105.4 stop_lost

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.75

Variant links:

Genes affected

ALG12 (HGNC:19358): (ALG12 alpha-1,6-mannosyltransferase) This gene encodes a member of the glycosyltransferase 22 family. The encoded protein catalyzes the addition of the eighth mannose residue in an alpha-1,6 linkage onto the dolichol-PP-oligosaccharide precursor (dolichol-PP-Man(7)GlcNAc(2)) required for protein glycosylation. Mutations in this gene have been associated with congenital disorder of glycosylation type Ig (CDG-Ig)characterized by abnormal N-glycosylation. [provided by RefSeq, Jul 2008]

ALG12 links:

ENSG00000273192 (HGNC:):

ENSG00000273192 links:

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM4

Stoplost variant in NM_024105.4 Downstream stopcodon found after 27 codons.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ALG12	NM_024105.4 link	c.1467A>C	p.Ter489Cysext*?	stop_lost	Exon 10 of 10	ENST00000330817.11	NP_077010.1	Q9BV10A0A024R4V6
ALG12	XM_017028936.2 link	c.1238+341A>C		intron_variant	Intron 9 of 9		XP_016884425.1
ALG12	XM_017028937.2 link	c.1238+341A>C		intron_variant	Intron 9 of 10		XP_016884426.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
ALG12	ENST00000330817.11 link	c.1467A>C	p.Ter489Cysext*?	stop_lost	Exon 10 of 10	1	NM_024105.4	ENSP00000333813.5	Q9BV10
ALG12	ENST00000486602.1 link	c.485A>C	p.Glu162Ala	missense_variant	Exon 4 of 4	3		ENSP00000420630.1	H7C5R7
ENSG00000273192	ENST00000610245.1 link	n.1611T>G		non_coding_transcript_exon_variant	Exon 1 of 1	6
ALG12	ENST00000492791.1 link	n.*286A>C		downstream_gene_variant		3		ENSP00000417387.1	H7C4I6

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1461820

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727226

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53386

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1111986

Other (OTH)

AF:

0.00

AC:

AN:

60390

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.450

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

Alfa

AF:

0.00

Hom.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

ALG12-congenital disorder of glycosylation

Uncertain:1

Apr 29, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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. This variant has not been reported in the literature in individuals affected with ALG12-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change disrupts the translational stop signal of the ALG12 mRNA. It is expected to extend the length of the ALG12 protein by 29 additional amino acid residues. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.27

BayesDel_noAF

Benign

-0.62

CADD

Benign

(source)

DANN

Benign

0.60

Eigen

Uncertain

0.46

Eigen_PC

Benign

0.16

FATHMM_MKL

Uncertain

0.83

PhyloP100

1.7

Vest4

0.0030

GERP RS

2.0

Mutation Taster

=67/133

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

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

Below is the list of publications found by LitVar for variant 22:49903838 T>G . It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over