Variant chr21-36765158-C-CA details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1PM2PP5

The NM_001352514.2(HLCS):c.1974dupT(p.Val659CysfsTer65) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000217 in 1,614,112 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00023 ( 0 hom. )

Consequence

HLCS
NM_001352514.2 frameshift

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:7U:1

Conservation

PhyloP100: -1.40

Variant links:

Genes affected

HLCS (HGNC:4976): (holocarboxylase synthetase) This gene encodes an enzyme that catalyzes the binding of biotin to carboxylases and histones. The protein plays an important role in gluconeogenesis, fatty acid synthesis and branched chain amino acid catabolism. Defects in this gene are the cause of holocarboxylase synthetase deficiency. Multiple alternatively spliced variants, encoding the same protein, have been identified.[provided by RefSeq, Jun 2011]

HLCS links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 11 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 21-36765158-C-CA is Pathogenic according to our data. Variant chr21-36765158-C-CA is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 370850.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=5, Likely_pathogenic=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HLCS	NM_001352514.2 link	c.1974dupT	p.Val659CysfsTer65	frameshift_variant	Exon 8 of 11	ENST00000674895.3	NP_001339443.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HLCS	ENST00000674895.3 link	c.1974dupT	p.Val659CysfsTer65	frameshift_variant	Exon 8 of 11		NM_001352514.2	ENSP00000502087.2		P50747-2A0A8C8QSB1

Frequencies

GnomAD3 genomes

AF:

0.0000854

AC:

AN:

152230

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.000118

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000477

AC:

AN:

251434

Hom.:

AF XY:

0.0000589

AC XY:

AN XY:

135902

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.00

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:

0.0000967

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000231

AC:

337

AN:

1461882

Hom.:

Cov.:

AF XY:

0.000237

AC XY:

172

AN XY:

727244

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000224

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:

0.000296

Gnomad4 OTH exome

AF:

0.0000993

GnomAD4 genome

AF:

0.0000854

AC:

AN:

152230

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74372

show subpopulations

Gnomad4 AFR

AF:

0.0000724

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000118

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000130

Hom.:

Bravo

AF:

0.0000529

EpiCase

AF:

0.000109

EpiControl

AF:

0.000356

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:7Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Holocarboxylase synthetase deficiency

Pathogenic:5Uncertain:1

Jun 21, 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.Val512Cysfs*65) in the HLCS gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in HLCS are known to be pathogenic (PMID: 16134170). This variant is present in population databases (rs767533946, gnomAD 0.009%). This premature translational stop signal has been observed in individual(s) with a mitochondrial disorder (PMID: 24215330). ClinVar contains an entry for this variant (Variation ID: 370850). For these reasons, this variant has been classified as Pathogenic. -

Dec 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The HLCS c.1533dupT (p.Val512CysfsTer65) variant is a frameshift variant that is predicted to result in premature termination of the protein. The p.Val512CysfsTer65 variant has been reported in two studies, in which it is found in two individuals with holocarboxylase synthetase deficiency, including in a compound heterozygous state in one individual and in a heterozygous state in a second individual who also carries two additional missense variants of unknown phase (DaRe et al. 2013; Reid et al. 2016). Control data are unavailable for this variant, which is reported at a frequency of 0.000095 in the European (non-Finnish) population of the Genome Aggregation Database. Due to the potential impact of frameshift variants and evidence from the literature, the p.Val512CysfsTer65 variant is classified as a variant of unknown significance but suspicious for holocarboxylase synthetase deficiency. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -

Jul 22, 2016

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 01, 2019

Rady Children's Institute for Genomic Medicine, Rady Children's Hospital San Diego

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This frameshifting variant in exon 9 of 12 introduces a premature stop codon and is therefore predicted to result in loss of normal protein function. This variant has been previously reported as a heterozygous change in two patients with suspected metabolic disease (PMID 24215330, 27604308) and classified in the ClinVar database as Likely Pathogenic by a clinical laboratory (Variation ID: 370850). It is present in the heterozygous state in the gnomAD population database at a frequency of 0.001% (15/277210) and thus is presumed to be rare. Based on the available evidence, the c.1533dup, p.Val512CysfsTer65 variant is classified as Pathogenic. -

Jun 13, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 12, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases

Pathogenic:1

Sep 13, 2021

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1533dupT (p.V512Cfs*65) alteration, located in exon 9 (coding exon 6) of the HLCS gene, consists of a duplication of T at position 1533, causing a translational frameshift with a predicted alternate stop codon after 65 amino acids. This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. This alteration has been reported in the heterozygous state along with two other HLCS variants in a patient diagnosed with holocarboxylase synthetase deficiency; however, parental testing to determine the phase of these variants was not available (Reid, 2016). Based on the available evidence, this alteration is classified as pathogenic. -

not provided

Pathogenic:1

Oct 02, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Previously reported in a patient with a neurometabolic phenotype who was also found to have a second variant in the HLCS gene (Reid et al., 2016); Frameshift 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; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 24215330, 27604308, 33870574) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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

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