rs762811727
Variant summary
Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong
The NM_001425242.1(ALG8):c.-16C>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000355 in 1,606,700 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 (★★).
Frequency
Consequence
NM_001425242.1 5_prime_UTR_premature_start_codon_gain
Scores
Clinical Significance
Conservation
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ACMG classification
Our verdict: Pathogenic. The variant received 14 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
ALG8 | NM_024079.5 | c.535C>T | p.Arg179* | stop_gained | Exon 5 of 13 | ENST00000299626.10 | NP_076984.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000329 AC: 5AN: 151966Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 250972 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.0000357 AC: 52AN: 1454734Hom.: 0 Cov.: 29 AF XY: 0.0000345 AC XY: 25AN XY: 724102 show subpopulations
GnomAD4 genome AF: 0.0000329 AC: 5AN: 151966Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74224 show subpopulations
ClinVar
Submissions by phenotype
Polycystic liver disease 3 with or without kidney cysts Pathogenic:2
The stop gained p.R179* in ALG8 (NM_024079.5) has been previously reported in heterozygous state in patients with polycystic liver disease (Besse W et al,2017). It has been submitted to ClinVar as Pathogenic based on the same. The p.R179* variant is observed in 1/16,224 (0.0062%) alleles from individuals of African background in gnomAD Exomes and is novel (not in any individuals) in 1000 Genomes. This variant is predicted to cause loss of normal protein function through protein truncation. For these reasons, this variant has been classified as Pathogenic. -
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ALG8-related disorder Pathogenic:2
The ALG8 c.535C>T variant is predicted to result in premature protein termination (p.Arg179*). This variant was firstly reported in the heterozygous state in a polycystic liver disease (PLD) patient who also has kidney cysts (Besse et al. 2017. PubMed ID: 28375157). In a later study of assessing the relationship between truncating ALG8 variants and polycystic kidney disease (PKD), individuals who are heterozygous for ALG8 pathogenic or likely pathogenic variants, including this variant, were shown to have increased risk of a mild (atypical) cystic kidney disease phenotype on imaging (Apple et al. 2023. PubMed ID: 36574950). Of note, the majority of loss-of-function variants in ALG8 have been reported in association with autosomal recessive congenital disorder of glycosylation (Human Gene Mutation Database). This variant is reported in 7 of 282,326 alleles in the gnomAD database. Nonsense variants in ALG8 are expected to be pathogenic. This variant is interpreted as likely pathogenic for autosomal recessive ALG8-related disorders. For autosomal dominant polycystic kidney-spectrum phenotype, however, it is currently uncertain since there is limited evidence to support the gene-disease relationship (ALG8 at https://www.clinicalgenome.org/). -
PVS1, PS3_Moderate -
ALG8 congenital disorder of glycosylation;C4693472:Polycystic liver disease 3 with or without kidney cysts Pathogenic:1
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not provided Pathogenic:1
PP2, PVS1 -
ALG8 congenital disorder of glycosylation Pathogenic:1
This sequence change creates a premature translational stop signal (p.Arg179*) in the ALG8 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ALG8 are known to be pathogenic (PMID: 19862844). This variant is present in population databases (rs762811727, gnomAD 0.004%). This premature translational stop signal has been observed in individual(s) with kidney and/or liver cysts (PMID: 28375157, 36574950). ClinVar contains an entry for this variant (Variation ID: 492977). For these reasons, this variant has been classified as Pathogenic. -
Familial cystic renal disease Pathogenic:1
The c.535C>T variant results in a premature stop codon at position 179 (p.Arg179Ter) in the ALG8 gene.This nonsense mutation is predicted to cause loss of normal protein function either through truncated protein product, fulfilling the PVS1 criterion. The variant is extremely rare, with an allele frequency of <0.01% in gnomAD v4.1.0, supporting PM2. Clinically, it has been identified in four unrelated individuals with combined polycystic liver and kidney disease, a phenotype consistent with ALG8-related disease, providing evidence for PP4 (Jawaid, 2025). Given the nature of the mutation, its rarity in population databases, and its consistent presence in affected individuals, the variant is classified as pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at