21-36756558-G-A

Position:

chr21-36756558-G-A

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong

The NM_001352514.2(HLCS):c.2434C>T(p.Arg812Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000292 in 1,610,630 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 Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R812R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000040 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000028 ( 0 hom. )

Consequence

HLCS
NM_001352514.2 stop_gained

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 5.64

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 14 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 6 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 21-36756558-G-A is Pathogenic according to our data. Variant chr21-36756558-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 203770.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HLCS	NM_001352514.2 linkuse as main transcript	c.2434C>T	p.Arg812Ter	stop_gained	10/11	ENST00000674895.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HLCS	ENST00000674895.3 linkuse as main transcript	c.2434C>T	p.Arg812Ter	stop_gained	10/11		NM_001352514.2	P4	P50747-2

Frequencies

GnomAD3 genomes

AF:

0.0000396

AC:

AN:

151536

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000657

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.0000958

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000589

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000278

AC:

AN:

251488

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135918

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000527

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000281

AC:

AN:

1459094

Hom.:

Cov.:

AF XY:

0.0000289

AC XY:

AN XY:

725944

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000506

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.0000563

Gnomad4 NFE exome

AF:

0.0000288

Gnomad4 OTH exome

AF:

0.0000498

GnomAD4 genome

AF:

0.0000396

AC:

AN:

151536

Hom.:

Cov.:

AF XY:

0.0000406

AC XY:

AN XY:

73976

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000657

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.0000958

Gnomad4 NFE

AF:

0.0000589

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000166

Hom.:

Bravo

AF:

0.0000189

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.0000412

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Holocarboxylase synthetase deficiency

Pathogenic:7

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jul 08, 2022	Variant summary: HLCS c.1993C>T (p.Arg665X) 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. In at least one experimental study, a truncation downstream of this position was found to impair biotinylating activity, suggesting the C-terminal end of the protein is important for its functional activity (e.g. Campeau_2001). The variant allele was found at a frequency of 2.8e-05 in 251488 control chromosomes (gnomAD). c.1993C>T has been reported in the literature in individuals affected with Holocarboxylase Synthetase Deficiency (e.g. Suzuki 2005, Donti 2016, Tangeraas_2020). These data indicate that the variant is likely to be associated with disease. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. All laboratories classified the variant as likely pathogenic (n=3) or pathogenic (n=1). Based on the evidence outlined above, the variant was classified as pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jan 20, 2021	- -
Likely pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Dec 30, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 22, 2024	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 29, 2024	This sequence change creates a premature translational stop signal (p.Arg665) in the HLCS gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 62 amino acid(s) of the HLCS protein. This variant is present in population databases (rs146448211, gnomAD 0.006%). This premature translational stop signal has been observed in individuals with holocarboxylase synthetase deficiency (PMID: 16134170, 27114915, 33123633). ClinVar contains an entry for this variant (Variation ID: 203770). This variant disrupts the C-terminus of the HLCS protein. Other variant(s) that disrupt this region (p.Arg665Aspfs41) have been observed in individuals with HLCS-related conditions (PMID: 10190325). This suggests that this may be a clinically significant region of the protein. For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Jan 20, 2017	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Mar 16, 2022	- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.51

BayesDel_noAF

Pathogenic

0.55

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Uncertain

0.56

Eigen_PC

Uncertain

0.36

FATHMM_MKL

Uncertain

0.79

MutationTaster

Benign

1.0

D;D

Vest4

0.79

GERP RS

3.6

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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