Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PVS1PM2PP3PP5_Very_Strong
The NM_000195.5(HPS1):c.397G>T(p.Glu133*) variant causes a stop gained, splice region change. The variant allele was found at a frequency of 0.000000684 in 1,461,786 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
HPS1 (HGNC:5163): (HPS1 biogenesis of lysosomal organelles complex 3 subunit 1) This gene encodes a protein that may play a role in organelle biogenesis associated with melanosomes, platelet dense granules, and lysosomes. The encoded protein is a component of three different protein complexes termed biogenesis of lysosome-related organelles complex (BLOC)-3, BLOC4, and BLOC5. Mutations in this gene are associated with Hermansky-Pudlak syndrome type 1. Alternative splicing results in multiple transcript variants. A pseudogene related to this gene is located on chromosome 22. [provided by RefSeq, Aug 2015]
Verdict is Pathogenic. Variant got 19 ACMG points.
PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.
PP5
Variant 10-98435273-C-A is Pathogenic according to our data. Variant chr10-98435273-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 5281.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Jun 01, 1998
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only
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not provided Pathogenic:1
Jan 29, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change creates a premature translational stop signal (p.Glu133*) in the HPS1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in HPS1 are known to be pathogenic (PMID: 12442288, 16185271). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with Hermansky-Pudlak syndrome (PMID: 9705234). ClinVar contains an entry for this variant (Variation ID: 5281). For these reasons, this variant has been classified as Pathogenic. -