NM_024079.5:c.1038+1G>T

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PVS1PP5

The NM_024079.5(ALG8):c.1038+1G>T variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.000104 in 1,613,992 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00010 ( 0 hom. )

Consequence

ALG8
NM_024079.5 splice_donor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:1

Conservation

PhyloP100: 7.07

Publications

2 publications found

Variant links:

Genes affected

ALG8 (HGNC:23161): (ALG8 alpha-1,3-glucosyltransferase) This gene encodes a member of the ALG6/ALG8 glucosyltransferase family. The encoded protein catalyzes the addition of the second glucose residue to the lipid-linked oligosaccharide precursor for N-linked glycosylation of proteins. Mutations in this gene have been associated with congenital disorder of glycosylation type Ih (CDG-Ih). Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]

ALG8 Gene-Disease associations (from GenCC):

ALG8-congenital disorder of glycosylation
Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: PanelApp Australia, G2P, Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
polycystic liver disease 3 with or without kidney cysts
Inheritance: AD Classification: STRONG, LIMITED Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp

ALG8 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.

PP5

Variant 11-78109441-C-A is Pathogenic according to our data. Variant chr11-78109441-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 492976.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_024079.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein
ALG8	NM_024079.5	MANE Select	c.1038+1G>T	splice_donor intron	N/A	NP_076984.2
ALG8	NM_001425224.1		c.1131+1G>T	splice_donor intron	N/A	NP_001412153.1
ALG8	NM_001425225.1		c.1038+1G>T	splice_donor intron	N/A	NP_001412154.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein
ALG8	ENST00000299626.10	TSL:1 MANE Select	c.1038+1G>T	splice_donor intron	N/A	ENSP00000299626.5
ALG8	ENST00000679559.1		c.1038+1G>T	splice_donor intron	N/A	ENSP00000505433.1
ALG8	ENST00000532440.6	TSL:3	c.1038+1G>T	splice_donor intron	N/A	ENSP00000433429.2

Frequencies

GnomAD3 genomes

AF:

0.000131

AC:

AN:

152132

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00170

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000263

AC:

AN:

251416

AF XY:

0.000258

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00268

Gnomad NFE exome

AF:

0.0000616

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000101

AC:

148

AN:

1461860

Hom.:

Cov.:

AF XY:

0.000113

AC XY:

AN XY:

727230

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33476

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00256

AC:

137

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000719

AC:

AN:

1111990

Other (OTH)

AF:

0.0000497

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.479

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000131

AC:

AN:

152132

Hom.:

Cov.:

AF XY:

0.000202

AC XY:

AN XY:

74318

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41426

American (AMR)

AF:

0.00

AC:

AN:

15266

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00170

AC:

AN:

10602

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68018

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.510

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000428

Hom.:

ExAC

AF:

0.000165

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Polycystic liver disease 3 with or without kidney cysts

Pathogenic:1Uncertain:1

Feb 21, 2018

OMIM

Significance:Pathogenic

Review Status:flagged submission

Collection Method:literature only

Sep 19, 2023

MVZ Martinsried, Medicover Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Familial cystic renal disease

Pathogenic:1

Jun 01, 2025

Mayo Translational Polycystic Kidney Disease Center, Mayo Clinic

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

The c.1038+1G>T variant in the ALG8 gene affects the invariant splice donor site of intron 10, a position critical for normal mRNA splicing. Alterations at this position are predicted to disrupt canonical splicing, likely resulting in aberrant transcripts and subsequent loss of function of the ALG8 protein. This variant has been previously reported in a patient with autosomal dominant polycystic liver disease (Besse et al., 2017), supporting its clinical relevance. Given that loss-of-function (LoF) is an established disease mechanism for ALG8-associated disorders, this variant satisfies PVS1. Additionally, it is extremely rare in population databases (allele frequency <0.01% in gnomAD v4.1.0), supporting PM2. Based on this evidence, the variant is classified as pathogenic.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.50

BayesDel_noAF

Pathogenic

0.44

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.1

FATHMM_MKL

Pathogenic

0.99

PhyloP100

7.1

GERP RS

5.7

Mutation Taster

=0/100

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.94

SpliceAI score (max)

0.68

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.68

Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over