rs764148793

Positions:

chr21-36754349-C-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_001352514.2(HLCS):c.2519G>C(p.Gly840Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000248 in 1,613,784 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 Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

HLCS
NM_001352514.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 7.10

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:

HLCS (HGNC:):

HLCS links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.993

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HLCS	NM_001352514.2 linkuse as main transcript	c.2519G>C	p.Gly840Ala	missense_variant	11/11	ENST00000674895.3	NP_001339443.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HLCS	ENST00000674895.3 linkuse as main transcript	c.2519G>C	p.Gly840Ala	missense_variant	11/11		NM_001352514.2	ENSP00000502087.2		P50747-2A0A8C8QSB1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152106

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000798

AC:

AN:

250760

Hom.:

AF XY:

0.0000148

AC XY:

AN XY:

135566

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000579

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461678

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727120

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000671

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152106

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74298

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Sep 17, 2021

Variant summary: HLCS c.2078G>C (p.Gly693Ala) results in a non-conservative amino acid change located in the Biotin protein ligase, C-terminal (IPR003142) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 250760 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.2078G>C has been reported in the literature as a compound heterozygous genotype in at-least one individual affected with Holocarboxylase Synthetase Deficiency (example, Donti_2016) and has been subsequently cited by others (example, Watabe_2018, Zheng_2020). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation and classified the variant as uncertain significance citing an overlapping evidence utilized in the context of this evaluation. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Holocarboxylase synthetase deficiency

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Counsyl

Aug 08, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.83

BayesDel_addAF

Pathogenic

0.43

BayesDel_noAF

Pathogenic

0.57

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.84

D;D;D

Eigen

Pathogenic

0.90

Eigen_PC

Pathogenic

0.81

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.91

D;.;.

M_CAP

Pathogenic

0.56

MetaRNN

Pathogenic

0.99

D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.6

H;H;H

PrimateAI

Uncertain

0.58

PROVEAN

Pathogenic

-4.9

.;D;D

REVEL

Pathogenic

0.85

Sift

Pathogenic

0.0

.;D;D

Sift4G

Pathogenic

0.0

D;D;D

Polyphen

1.0

D;D;D

Vest4

0.97

MutPred

0.92

Loss of loop (P = 0.1242);Loss of loop (P = 0.1242);Loss of loop (P = 0.1242);

MVP

0.98

MPC

0.60

ClinPred

0.96

GERP RS

6.2

Varity_R

0.93

gMVP

0.88

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

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