rs147138516
Variant summary
Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM1BS2
The NM_000157.4(GBA1):c.535G>C(p.Asp179His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000128 in 1,613,390 control chromosomes in the GnomAD database, including 2 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Consequence
NM_000157.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -2 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
GBA1 | NM_000157.4 | c.535G>C | p.Asp179His | missense_variant | Exon 5 of 11 | ENST00000368373.8 | NP_000148.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000158 AC: 24AN: 151754Hom.: 0 Cov.: 29
GnomAD3 exomes AF: 0.000135 AC: 34AN: 250934Hom.: 1 AF XY: 0.000125 AC XY: 17AN XY: 135674
GnomAD4 exome AF: 0.000125 AC: 182AN: 1461636Hom.: 2 Cov.: 33 AF XY: 0.000110 AC XY: 80AN XY: 727132
GnomAD4 genome AF: 0.000158 AC: 24AN: 151754Hom.: 0 Cov.: 29 AF XY: 0.000189 AC XY: 14AN XY: 74104
ClinVar
Submissions by phenotype
not provided Uncertain:3
Identified in siblings with low beta-glucocerebrosidase activity and discordant phenotypes; these siblings were also compound heterozygous for another variant in GBA. One sibling had neuronopathic Gaucher and the other was nearly asymptomatic at the age of 60. The authors attribute the difference in GBA activity and phenotype to a heterozygous variant in SCARB2, a beta-glucocerebrosidase transporter, identified only in the severely affected sibling. More evidence is needed to evaluate the pathogenicity of D179H (PMID: 21796727, 22623374); Identified in the heterozygous state in patients with Lewy body dementia and with Parkinson disease with dementia; however, D179H was also identified in the heterozygous state in control individuals used in some of these studies (PMID: 32618053, 27717005, 23588557, 29948939, 31809948); In silico analysis supports that this missense variant does not alter protein structure/function; Also known as p.D140H; This variant is associated with the following publications: (PMID: 18160322, 30777654, 31809948, 1864608, 23588557, 27717005, 29948939, 27397011, 22623374, 34308104, 32618053, 32191290, 36598340, 21796727) -
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not specified Uncertain:1
Variant summary: GBA c.535G>C (p.Asp179His) results in a non-conservative amino acid change located in the Glycosyl hydrolase family 30, TIM-barrel domain of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00016 in 260904 control chromosomes in the gnomAD database, including 1 homozygotes. This frequency is not significantly higher than estimated for a pathogenic variant in GBA causing Gaucher Disease (0.00016 vs 0.005), allowing no conclusion about variant significance. The variant was reported in the literature in a haplotype with c.1093G>A (p.Glu365Lys) in compound heterozygosity with c.586A>C (p.Lys196Gln) in two brothers diagnosed with Type I Gaucher disease (GD) and subsequently reported in another study with an overlapping cohort (Example, Eyal_1991, Park_2003). These data indicate that the variant may be associated with Gaucher Disease. In functional studies, the c.535G>C variant alone was shown to result in a mild reduction of enzyme activity (approximately 50-74% residual activity), while the presence of the complex allele c.535G>C + c.1093G>A resulted in significantly decreased activity compared to either individual allele (20-25% residual activity; Grace_1999, Ron_2005). The c.535G>C variant and c.535G>C + c.1093G>A complex allele have also been reported as single alleles or as non-informative genotypes (second allele not specified) in patients with Parkinson's Disease (PD) and dementia, and it has been suggested that monoallelic variants in GBA may be risk factors for PD, but a pathogenic contribution of this variant towards these associations have not been conclusively determined (Example, Lesage_2011, Meeus_2012, Tsuang_2012, Nalls_2013, Crosiers_2016, Liu_2016, Mata_2016, Blauwendraat_2017, Moors_2019, Geut_2019, den Heijer_2020, Oliveira_2021). Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and all classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Gaucher disease Uncertain:1
The p.Asp179His variant in GBA has been reported in at least 3 individuals with Gaucher disease (PMID: 22350617, 22623374, 10079102) and has been identified in 0.027% (35/128762) of European (non-Finnish) chromosomes, including 1 homozygote, by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs147138516). Although this variant has been seen in the general population, its frequency is not high enough to rule out a pathogenic role. This variant has also been reported in ClinVar (VariationID: 242811) as likely pathogenic by Integrated Genetics and as a VUS by Praxis fuer Humangenetik Tuebingen. In vitro functional studies provide some evidence that the p.Asp179His variant may not impact protein function (PMID: 21831682, 10079102). However, these types of assays may not accurately represent biological function. Computational prediction tools and conservation analyses do not provide strong support for or against an impact to the protein. The presence of this variant in combination with a reported pathogenic variant and in an individual with Gaucher disease increases the likelihood that the p.Asp179His variant is pathogenic (VariationID: 4297; PMID: 22350617). In summary, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: BS3_supporting, PM3_supporting (Richards 2015). -
Gaucher disease perinatal lethal Uncertain:1
Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3B. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with Gaucher disease (MIM# 230800, 230900, 231000, 231005, 608013). (I) 0106 - This gene is associated with autosomal recessive disease. The different types of Gaucher disease are considered to fall within a spectrum, rather than distinct conditions, and are determined by age of disease onset and the presence and severity of neurologic function. Specific counseling about individual case prognosis is hindered by a significant overlap in the clinical features of individuals with various genotypes (OMIM, PMID: 20301446). (I) 0115 - Variants in this gene are known to have variable expressivity. Gaucher disease is associated with marked clinical variability, even within the same family (PMID: 31010158). (I) 0200 - Variant is predicted to result in a missense amino acid change from aspartic acid to histidine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v2 and v3) <0.01 for a recessive condition (56 heterozygotes, 1 homozygote). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v2) (1 heterozygote, 0 homozygotes). (I) 0502 - Missense variant with conflicting in silico predictions and uninformative conservation. (I) 0600 - Variant is located in the annotated glycosol hydrolase family 20 TIM-barrel domain (DECIPHER). (I) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0809 - Previous evidence of pathogenicity for this variant is inconclusive. This variant has been classified as a VUS by several clinical laboratories in ClinVar, and has been observed as part of a complex allele with p.(Glu365Lys) in one family with Gaucher disease where it was observed to be compound heterozygous (PMID: 1864608). This complex allele has also been described as a risk allele for parkinsons disease (PMID: 36598340). (I) 0903 - This variant has limited evidence for segregation with disease. This variant as part of a complex allele with p.(Glu365Lys) was observed as compound heterozygous in two brothers with Gaucher disease. Other unaffected families members were either only heterozygous for one of the alleles or were not a carrier of either (PMID: 1864608). (SP) 1002 - This variant has moderate functional evidence supporting abnormal protein function. This variant has been shown to only reduce b-glucosidase activity to 50% by itself, but in a complex allele with p.(Glu365Lys) it reduced enzyme activity to only 20% of normal activity (PMID: 10079102). (SP) 1206 - This variant has been shown to be paternally inherited (by trio analysis). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at