5-75345615-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_000859.3(HMGCR):c.407G>A(p.Arg136Lys) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,460,832 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: HMGCR NM_000859.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.67

Genes affected

HMGCR (HGNC:5006): (3-hydroxy-3-methylglutaryl-CoA reductase) HMG-CoA reductase is the rate-limiting enzyme for cholesterol synthesis and is regulated via a negative feedback mechanism mediated by sterols and non-sterol metabolites derived from mevalonate, the product of the reaction catalyzed by reductase. Normally in mammalian cells this enzyme is suppressed by cholesterol derived from the internalization and degradation of low density lipoprotein (LDL) via the LDL receptor. Competitive inhibitors of the reductase induce the expression of LDL receptors in the liver, which in turn increases the catabolism of plasma LDL and lowers the plasma concentration of cholesterol, an important determinant of atherosclerosis. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Aug 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, HMGCR
• BP4: Computational evidence support a benign effect (MetaRNN=0.105896264).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HMGCR	NM_000859.3	c.407G>A	p.Arg136Lys	missense_variant	5/20	ENST00000287936.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HMGCR	ENST00000287936.9	c.407G>A	p.Arg136Lys	missense_variant	5/20	1	NM_000859.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251224 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135782

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460832 Hom.: 0 Cov.: 28 AF XY: 0.00000275 AC XY: 2 AN XY: 726812

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 01, 2023

The c.407G>A (p.R136K) alteration is located in exon 5 (coding exon 4) of the HMGCR gene. This alteration results from a G to A substitution at nucleotide position 407, causing the arginine (R) at amino acid position 136 to be replaced by a lysine (K). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.086
BayesDel_addAF	Benign	-0.016	T
BayesDel_noAF	Benign	-0.16
Cadd	Benign	21
Dann	Benign	0.85
DEOGEN2	Uncertain	0.60	D;D;.
Eigen	Benign	-0.32
Eigen_PC	Benign	-0.014
FATHMM_MKL	Uncertain	0.97	D
M_CAP	Benign	0.028	D
MetaRNN	Benign	0.11	T;T;T
MetaSVM	Uncertain	-0.14	T
MutationAssessor	Benign	-1.7	N;N;N
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	2.0	N;N;N
REVEL	Uncertain	0.40
Sift	Benign	1.0	T;T;T
Sift4G	Benign	1.0	T;T;T
Polyphen		0.0030	B;B;B
Vest4		0.18
MutPred		0.66		Gain of ubiquitination at R136 (P = 0.0238);Gain of ubiquitination at R136 (P = 0.0238);Gain of ubiquitination at R136 (P = 0.0238);
MVP		0.70
MPC		0.84
ClinPred		0.32	T
GERP RS		5.7
Varity_R		0.21
gMVP		0.50

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs781639869; hg19: chr5-74641440;