9-99217992-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP3_Moderate PP5

The NM_033087.4(ALG2):c.1193T>C(p.Phe398Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,890 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: ALG2 NM_033087.4 missense
• Clinical Significance: Likely pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 8.87

Genes affected

ALG2 (HGNC:23159): (ALG2 alpha-1,3/1,6-mannosyltransferase) This gene encodes a member of the glycosyltransferase 1 family. The encoded protein acts as an alpha 1,3 mannosyltransferase, mannosylating Man(2)GlcNAc(2)-dolichol diphosphate and Man(1)GlcNAc(2)-dolichol diphosphate to form Man(3)GlcNAc(2)-dolichol diphosphate. Defects in this gene have been associated with congenital disorder of glycosylation type Ih (CDG-Ii). Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.908
• PP5: Variant 9-99217992-A-G is Pathogenic according to our data. Variant chr9-99217992-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2498382.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ALG2	NM_033087.4	c.1193T>C	p.Phe398Ser	missense_variant	2/2	ENST00000476832.2
ALG2	XM_047423996.1	c.914T>C	p.Phe305Ser	missense_variant	2/2
ALG2	NR_024532.2	n.1400T>C		non_coding_transcript_exon_variant	3/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ALG2	ENST00000476832.2	c.1193T>C	p.Phe398Ser	missense_variant	2/2	1	NM_033087.4	P1
ALG2	ENST00000319033.7	c.914T>C	p.Phe305Ser	missense_variant	2/2	1
ALG2	ENST00000238477.5	c.*935T>C		3_prime_UTR_variant, NMD_transcript_variant	3/3	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461890 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Congenital myasthenic syndrome 14 Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Payam Genetics Center, General Welfare Department of North Khorasan Province

Mar 01, 2023

The ALG2 c.1193T>C(p.Phe398Ser) results is a missense mutation and results at the protein level is a dysfunctional protein, predicted lead to disease. This variant is not present in population databases (ExAC no frequency) and was not found in 1000G, Genom AD exome, genome and Iranom. This variant has not been reported in the literature in individuals affected with ALG2-related conditions . We classified this variant as Pathogenic according to the our clinical evidence from this patient. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
Cadd	Pathogenic	28
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.50	T;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Pathogenic	0.63	D
MetaRNN	Pathogenic	0.91	D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Pathogenic	4.1	H;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.60	T
PROVEAN	Pathogenic	-7.7	D;D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.94
MutPred		0.63		Gain of disorder (P = 0.0109);.;
MVP		0.99
MPC		1.0
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.97
gMVP		0.91

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: rs1828723159; hg19: chr9-101980274;