chr22-49903837-C-G

Position:

• chr22-49903837-C-G

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The NM_024105.4(ALG12):​c.*1G>C variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0031 in 1,614,178 control chromosomes in the GnomAD database, including 8 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.0020 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0032 (8 hom.)
• Consequence: ALG12 NM_024105.4 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 0.277

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]

(HGNC:):

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.79).
• BS1: Variant frequency is greater than expected in population amr. gnomad4 allele frequency = 0.00202 (307/152338) while in subpopulation AMR AF= 0.0034 (52/15310). AF 95% confidence interval is 0.00283. There are 0 homozygotes in gnomad4. There are 146 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High Homozygotes in GnomAdExome4 at 8 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ALG12	NM_024105.4	c.*1G>C		3_prime_UTR_variant	10/10	ENST00000330817.11	NP_077010.1
ALG12	XM_017028936.2	c.1238+342G>C		intron_variant			XP_016884425.1
ALG12	XM_017028937.2	c.1238+342G>C		intron_variant			XP_016884426.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ALG12	ENST00000330817.11	c.*1G>C		3_prime_UTR_variant	10/10	1	NM_024105.4	ENSP00000333813	P1
	ENST00000610245.1	n.1610C>G		non_coding_transcript_exon_variant	1/1
ALG12	ENST00000486602.1	c.489G>C	p.Glu163Asp	missense_variant	4/4	3		ENSP00000420630

Frequencies

GnomAD3 genomes AF: 0.00201 AC: 306 AN: 152220 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.000699

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00340

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000621

Gnomad FIN AF: 0.000470

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00316

Gnomad OTH AF: 0.000955

GnomAD3 exomes AF: 0.00219 AC: 547 AN: 250266 Hom.: 1 AF XY: 0.00225 AC XY: 305 AN XY: 135564

Gnomad AFR exome AF: 0.000631

Gnomad AMR exome AF: 0.00197

Gnomad ASJ exome AF: 0.000497

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.000784

Gnomad FIN exome AF: 0.000185

Gnomad NFE exome AF: 0.00366

Gnomad OTH exome AF: 0.00345

GnomAD4 exome AF: 0.00322 AC: 4703 AN: 1461840 Hom.: 8 Cov.: 32 AF XY: 0.00324 AC XY: 2356 AN XY: 727228

Gnomad4 AFR exome AF: 0.000299

Gnomad4 AMR exome AF: 0.00201

Gnomad4 ASJ exome AF: 0.000536

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.000684

Gnomad4 FIN exome AF: 0.000243

Gnomad4 NFE exome AF: 0.00390

Gnomad4 OTH exome AF: 0.00275

GnomAD4 genome AF: 0.00202 AC: 307 AN: 152338 Hom.: 0 Cov.: 33 AF XY: 0.00196 AC XY: 146 AN XY: 74478

Gnomad4 AFR AF: 0.000697

Gnomad4 AMR AF: 0.00340

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000622

Gnomad4 FIN AF: 0.000470

Gnomad4 NFE AF: 0.00318

Gnomad4 OTH AF: 0.000945

Alfa AF: 0.00237 Hom.: 0

Bravo AF: 0.00208

Asia WGS AF: 0.000577 AC: 2 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Apr 08, 2014	- -
Uncertain significance, criteria provided, single submitter	not provided	Breakthrough Genomics, Breakthrough Genomics	-	- -

ALG12-congenital disorder of glycosylation Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.79
CADD	Benign	5.8
DANN	Benign	0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs138804791; hg19: chr22-50297485; COSMIC: COSV58208222; COSMIC: COSV58208222;