rs139794766
Variant summary
Our verdict is Benign. The variant received -7 ACMG points: 2P and 9B. PM5BP4_StrongBP6BS1
The NM_005529.7(HSPG2):c.5297C>T(p.Ala1766Val) variant causes a missense change. The variant allele was found at a frequency of 0.000464 in 1,613,514 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1766T) has been classified as Likely pathogenic.
Frequency
Consequence
NM_005529.7 missense
Scores
Clinical Significance
Conservation
Publications
- Schwartz-Jampel syndrome type 1Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), G2P
- Silverman-Handmaker type dyssegmental dysplasiaInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, ClinGen, Labcorp Genetics (formerly Invitae)
- Schwartz-Jampel syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Benign. The variant received -7 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| HSPG2 | NM_005529.7 | c.5297C>T | p.Ala1766Val | missense_variant | Exon 43 of 97 | ENST00000374695.8 | NP_005520.4 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| HSPG2 | ENST00000374695.8 | c.5297C>T | p.Ala1766Val | missense_variant | Exon 43 of 97 | 1 | NM_005529.7 | ENSP00000363827.3 |
Frequencies
GnomAD3 genomes AF: 0.000329 AC: 50AN: 152146Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000584 AC: 146AN: 250104 AF XY: 0.000732 show subpopulations
GnomAD4 exome AF: 0.000478 AC: 699AN: 1461250Hom.: 1 Cov.: 34 AF XY: 0.000552 AC XY: 401AN XY: 726926 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000328 AC: 50AN: 152264Hom.: 0 Cov.: 32 AF XY: 0.000363 AC XY: 27AN XY: 74440 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:2Benign:1
- -
The A1766V variant in the HSPG2 gene has not been reported previously as a pathogenic variant, nor as a benign variant, to our knowledge. The A1766V variant is observed in 92/30776 (0.3%) alleles from individuals of South Asian background in large population cohorts, and 1 homozygous individual undergoing testing at GeneDx (Lek et al., 2016). The A1766V variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. In-silico analyses, including protein predictors and evolutionary conservation, support that this variant does not alter protein structure/function. We interpret A1766V as a variant of uncertain significance. -
The HSPG2 p.Ala1766Val variant was not identified in the literature nor was it identified in LOVD 3.0. The variant was identified in dbSNP (ID: rs139794766) and ClinVar (classified as likely benign by Athena Diagnostics and as uncertain significance by Illumina and GeneDx). The variant was identified in control databases in 162 of 281466 chromosomes at a frequency of 0.0005756 increasing the likelihood this could be a low frequency benign variant (Genome Aggregation Database March 6, 2019, v2.1.1). The variant was observed in the following populations: South Asian in 92 of 30610 chromosomes (freq: 0.003006), Other in 6 of 7204 chromosomes (freq: 0.000833), European (non-Finnish) in 53 of 128280 chromosomes (freq: 0.000413), Latino in 8 of 35398 chromosomes (freq: 0.000226) and African in 3 of 24894 chromosomes (freq: 0.000121), but was not observed in the Ashkenazi Jewish, East Asian, or European (Finnish) populations. The p.Ala1766 residue is conserved in mammals but not in more distantly related organisms however four out of five computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Connective tissue disorder Uncertain:1
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Lethal Kniest-like syndrome Benign:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -
not specified Benign:1
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HSPG2-related disorder Benign:1
This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -
Schwartz-Jampel syndrome Benign:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at