chr1-23825385-G-A

Variant names:

• chr1-23825385-G-A
• rs1212444447
• NM_000191.3:c.31C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000191.3(HMGCL):​c.31C>T​(p.Arg11*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000284 in 1,409,212 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 (★★). Synonymous variant affecting the same amino acid position (i.e. R11R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: HMGCL NM_000191.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: 0.289
• Publications: 1 publications found

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 Gene-Disease associations (from GenCC):

• 3-hydroxy-3-methylglutaric aciduria

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P, Orphanet, Myriad Women’s Health, ClinGen

LOC105376861 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 76 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-23825385-G-A is Pathogenic according to our data. Variant chr1-23825385-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 521752.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000191.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HMGCL	NM_000191.3	MANE Select	c.31C>T	p.Arg11*	stop_gained	Exon 1 of 9	NP_000182.2
	HMGCL	NM_001166059.2		c.31C>T	p.Arg11*	stop_gained	Exon 1 of 7	NP_001159531.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HMGCL	ENST00000374490.8	TSL:1 MANE Select	c.31C>T	p.Arg11*	stop_gained	Exon 1 of 9	ENSP00000363614.3
	HMGCL	ENST00000509389.5	TSL:1	n.43C>T		non_coding_transcript_exon	Exon 1 of 6
	HMGCL	ENST00000436439.6	TSL:2	c.31C>T	p.Arg11*	stop_gained	Exon 1 of 7	ENSP00000389281.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000121 AC: 2 AN: 165836 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000377

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000153

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000284 AC: 4 AN: 1409212 Hom.: 0 Cov.: 31 AF XY: 0.00000144 AC XY: 1 AN XY: 696428

African (AFR) AF: 0.00 AC: 0 AN: 31894

American (AMR) AF: 0.0000266 AC: 1 AN: 37550

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25256

East Asian (EAS) AF: 0.0000551 AC: 2 AN: 36272

South Asian (SAS) AF: 0.00 AC: 0 AN: 80052

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48650

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5670

European-Non Finnish (NFE) AF: 9.21e-7 AC: 1 AN: 1085510

Other (OTH) AF: 0.00 AC: 0 AN: 58358

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000508 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Deficiency of hydroxymethylglutaryl-CoA lyase Pathogenic:6

Sep 04, 2023

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.001%). Predicted Consequence/Location: Stop-gained (nonsense): predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000521752 /PMID: 25872961). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline.

Dec 07, 2017

Counsyl

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com.

Apr 11, 2023

Genome-Nilou Lab

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Jun 06, 2022

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Oct 30, 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.Arg11*) in the HMGCL gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in HMGCL are known to be pathogenic (PMID: 9817922, 17692550, 23465862). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This premature translational stop signal has been observed in individual(s) with HMGCL-related conditions (PMID: 25872961, 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: 521752). For these reasons, this variant has been classified as Pathogenic.

Apr 30, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Inborn genetic diseases Pathogenic:1

May 18, 2017

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Long chain 3-hydroxyacyl-CoA dehydrogenase deficiency Pathogenic:1

Nov 23, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.19
CADD	Pathogenic	35
DANN	Uncertain	0.99
Eigen	Benign	0.0012
Eigen_PC	Benign	-0.33
FATHMM_MKL	Benign	0.14	N
PhyloP100		0.29
Vest4		0.19
GERP RS		-0.45
PromoterAI		0.090	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.6
Mutation Taster		=19/181	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.11		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs1212444447; hg19: chr1-24151875;