chr1-23820545-C-A

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000191.3(HMGCL):c.109G>T(p.Glu37*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000279 in 1,614,004 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000072 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

HMGCL
NM_000191.3 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:12

Conservation

PhyloP100: 7.29

Variant links:

Genes affected

HMGCL (HGNC:5005): (3-hydroxy-3-methylglutaryl-CoA lyase) The protein encoded by this gene belongs to the HMG-CoA lyase family. It is a mitochondrial enzyme that catalyzes the final step of leucine degradation and plays a key role in ketone body formation. Mutations in this gene are associated with HMG-CoA lyase deficiency. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2009]

HMGCL links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 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;

PP5

Variant 1-23820545-C-A is Pathogenic according to our data. Variant chr1-23820545-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 195033.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-23820545-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HMGCL	NM_000191.3 link	c.109G>T	p.Glu37*	stop_gained	Exon 2 of 9	ENST00000374490.8	NP_000182.2	P35914-1
HMGCL	NM_001166059.2 link	c.109G>T	p.Glu37*	stop_gained	Exon 2 of 7		NP_001159531.1	P35914-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HMGCL	ENST00000374490.8 link	c.109G>T	p.Glu37*	stop_gained	Exon 2 of 9	1	NM_000191.3	ENSP00000363614.3		P35914-1

Frequencies

GnomAD3 genomes

AF:

0.0000723

AC:

AN:

152182

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000477

AC:

AN:

251488

Hom.:

AF XY:

0.0000515

AC XY:

AN XY:

135920

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000231

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000233

AC:

AN:

1461822

Hom.:

Cov.:

AF XY:

0.0000275

AC XY:

AN XY:

727218

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000246

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000198

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000723

AC:

AN:

152182

Hom.:

Cov.:

AF XY:

0.000108

AC XY:

AN XY:

74338

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000278

Hom.:

Bravo

AF:

0.000128

ExAC

AF:

0.0000247

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:12

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Deficiency of hydroxymethylglutaryl-CoA lyase

Pathogenic:9

Jun 11, 2018

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: HMGCL c.109G>T (p.Glu37X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 4.9e-05 in 246260 control chromosomes, which does not exceed the maximal expected allele frequency for a pathogenic variant in HMGCL. c.109G>T has been reported in the literature in multiple individuals affected with HMG-CoA Lyase Deficiency as both a homozygous and compound heterozygous allele. These data indicate that the variant is very likely to be associated with disease. In a report by Casale_1998, four patients homozygous for the variant had HMG-CoA lyase activity levels less than 10% of controls, indicating a severe reduction in enzyme activity caused by the variant. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Aug 09, 2018

Illumina Laboratory Services, Illumina

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The HMGCL c.109G>T (p.Glu37Ter) variant is a stop-gained variant that is predicted to cause premature truncation of the protein. In a selection of the available literature, the p.Glu37Ter variant was found in at least 11 unrelated individuals affected with 3-hydroxy-3-methylglutaryl-Coenzyme A lyase deficiency, including in eight individuals in a homozygous state, in two in a compound heterozygous state and in one in a heterozygous state in whom the second variant was not found (PiÃ© et al. 1997; Cardoso et al. 2004). The variant was shown to be absent from one control individual but is reported at a frequency of 0.000208 in the Latino population of the Genome Aggregation Database. In patiet fibroblasts, 3-hydroxy-3-methylglutaryl-Coenzyme A lyase activity was shown to be less than 3% of activity compared to the levels seen in healthy subjects (PiÃ© et al. 1997; Cardoso et al. 2004). RT-PCR analysis in patient fibroblasts showed that the variant resulted in skipping of exon 2 (PiÃ© et al. 1997). Based on the collective evidence and the potential impact of stop-gained variants, the p.Glu37Ter variant is classified as pathogenic for 3-hydroxy-3-methylglutaryl-Coenzyme A lyase deficiency. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -

Mar 30, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 28, 2017

Counsyl

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

May 10, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 16, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Apr 11, 2023

Genome-Nilou Lab

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 04, 2024

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.Glu37*) in the HMGCL gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 289 amino acid(s) of the HMGCL protein. This variant is present in population databases (rs763494292, gnomAD 0.02%). This premature translational stop signal has been observed in individual(s) with HMG-CoA lyase deficiency (PMID: 15308132, 19177531, 23465862, 28583327). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 195033). For these reasons, this variant has been classified as Pathogenic. -

Jan 06, 2023

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ACMG classification criteria: PVS1 very strong, PM2 supporting, PM3 strong, PP4 -

not provided

Pathogenic:2

Dec 04, 2014

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jun 01, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 19177531, 15752612, 18080783, 25525159, 9439591, 15308132, 17692550, 28583327, 28257639, 31589614, 28396157, 9163320, 23465862) -

Inborn genetic diseases

Pathogenic:1

Jun 18, 2021

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.109G>T (p.E37*) alteration, located in exon 2 (coding exon 2) of the HMGCL gene, consists of a G to T substitution at nucleotide position 109. This changes the amino acid from a glutamic acid (E) to a stop codon at amino acid position 37. This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. This mutation has been report in several homozygous and compound heterozygous individuals with HMG-CoA lyase deficiency (Pié, 1997; Cardoso, 2004; Menao, 2009; Muñoz-Bonet, 2017). Analysis of patient fibroblasts demonstrated that this mutation resulted in exon 2 skipping (Puisac, 2013). Based on the available evidence, this alteration is classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.43

BayesDel_noAF

Pathogenic

0.66

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Pathogenic

0.99

Vest4

0.48

ClinPred

0.89

GERP RS

5.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.18

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over