rs138086607

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 3P and 2B. PM2PP2BP4_Moderate

The NM_005518.4(HMGCS2):​c.894G>C​(p.Met298Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,860 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

HMGCS2
NM_005518.4 missense

Scores

1
18

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 0.923

Publications

2 publications found
Variant links:
Genes affected
HMGCS2 (HGNC:5008): (3-hydroxy-3-methylglutaryl-CoA synthase 2) The protein encoded by this gene belongs to the HMG-CoA synthase family. It is a mitochondrial enzyme that catalyzes the first reaction of ketogenesis, a metabolic pathway that provides lipid-derived energy for various organs during times of carbohydrate deprivation, such as fasting. Mutations in this gene are associated with HMG-CoA synthase deficiency. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Oct 2009]
HMGCS2 Gene-Disease associations (from GenCC):
  • 3-hydroxy-3-methylglutaryl-CoA synthase deficiency
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Orphanet, ClinGen, G2P

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 13 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: -0.19124 (below the threshold of 3.09). Trascript score misZ: 0.52753 (below the threshold of 3.09). GenCC associations: The gene is linked to 3-hydroxy-3-methylglutaryl-CoA synthase deficiency.
BP4
Computational evidence support a benign effect (MetaRNN=0.15626767).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HMGCS2NM_005518.4 linkc.894G>C p.Met298Ile missense_variant Exon 5 of 10 ENST00000369406.8 NP_005509.1 P54868-1A0A140VJL2
HMGCS2NM_001166107.1 linkc.768G>C p.Met256Ile missense_variant Exon 4 of 9 NP_001159579.1 P54868-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HMGCS2ENST00000369406.8 linkc.894G>C p.Met298Ile missense_variant Exon 5 of 10 1 NM_005518.4 ENSP00000358414.3 P54868-1
HMGCS2ENST00000544913.2 linkc.768G>C p.Met256Ile missense_variant Exon 4 of 9 2 ENSP00000439495.2 P54868-2
HMGCS2ENST00000472375.5 linkn.341G>C non_coding_transcript_exon_variant Exon 2 of 3 5
HMGCS2ENST00000476640.1 linkn.625G>C non_coding_transcript_exon_variant Exon 3 of 4 3

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461860
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727242
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111982
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.20
BayesDel_addAF
Benign
-0.12
T
BayesDel_noAF
Benign
-0.42
CADD
Benign
17
DANN
Benign
0.96
DEOGEN2
Benign
0.28
T;.
Eigen
Benign
-0.44
Eigen_PC
Benign
-0.23
FATHMM_MKL
Uncertain
0.88
D
LIST_S2
Benign
0.84
T;T
M_CAP
Benign
0.017
T
MetaRNN
Benign
0.16
T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.40
N;.
PhyloP100
0.92
PrimateAI
Benign
0.40
T
PROVEAN
Benign
-0.74
N;N
REVEL
Benign
0.14
Sift
Benign
0.35
T;T
Sift4G
Benign
0.57
T;T
Polyphen
0.0020
B;.
Vest4
0.24
MutPred
0.43
Gain of catalytic residue at M298 (P = 0.0065);.;
MVP
0.61
MPC
0.11
ClinPred
0.28
T
GERP RS
3.3
Varity_R
0.34
gMVP
0.49
Mutation Taster
=74/26
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs138086607; hg19: chr1-120300018; API