rs544956641

Positions:

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong

The NM_000187.4(HGD):c.365C>T(p.Ala122Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000248 in 1,613,906 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A122D) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

HGD
NM_000187.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 9.32

Variant links:

Genes affected

HGD (HGNC:4892): (homogentisate 1,2-dioxygenase) This gene encodes the enzyme homogentisate 1,2 dioxygenase. This enzyme is involved in the catabolism of the amino acids tyrosine and phenylalanine. Mutations in this gene are the cause of the autosomal recessive metabolism disorder alkaptonuria.[provided by RefSeq, May 2010]

HGD links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PM1

In a strand (size 7) in uniprot entity HGD_HUMAN there are 11 pathogenic changes around while only 0 benign (100%) in NM_000187.4

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.968

PP5

Variant 3-120650843-G-A is Pathogenic according to our data. Variant chr3-120650843-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 188865.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-120650843-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HGD	NM_000187.4 link	c.365C>T	p.Ala122Val	missense_variant	6/14	ENST00000283871.10	NP_000178.2	Q93099

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	UniProt
HGD	ENST00000283871.10 link	c.365C>T	p.Ala122Val	missense_variant	6/14	1	NM_000187.4	ENSP00000283871.5	Q93099
HGD	ENST00000476082.2 link	c.242C>T	p.Ala81Val	missense_variant	5/7	5		ENSP00000419560.2	C9JTX9
HGD	ENST00000485313.5 link	n.473C>T		non_coding_transcript_exon_variant	7/7	5
HGD	ENST00000492108.5 link	n.-5C>T		upstream_gene_variant		2		ENSP00000419838.1	H7C5G7

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152198

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000557

AC:

AN:

251388

Hom.:

AF XY:

0.0000442

AC XY:

AN XY:

135862

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000425

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000267

AC:

AN:

1461590

Hom.:

Cov.:

AF XY:

0.0000344

AC XY:

AN XY:

727128

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000429

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152316

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74482

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ExAC

AF:

0.0000576

AC:

Asia WGS

AF:

0.000577

AC:

AN:

3478

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Alkaptonuria

Pathogenic:7

Pathogenic, criteria provided, single submitter	clinical testing	Lifecell International Pvt. Ltd	-	A Homozygote Missense variant c.365C>T in Exon 6 of the HGD gene that results in the amino acid substitution p.Ala122Val was identified. The observed variant has a maximum allele frequency of 0.00006/--% in gnomAD exomes and genomes, respectively. The severity of the impact of this variant on the protein is medium, based on the effect of the protein and REVEL score . Rare Exome Variant Ensemble Learner (REVEL) is an ensembl method for predicting the pathogenicity of missense variants based on a combination of scores from 13 individual tools: MutPred, FATHMM v2.3, VEST 3.0, PolyPhen-2, SIFT, PROVEAN, MutationAssessor, MutationTaster, LRT, GERP++, SiPhy, phyloP, and phastCons. The REVEL score for an individual missense variant can range from 0 to 1, with higher scores reflecting greater likelihood that the variant is disease-causing. This variant has been reported as Pathogenic/Likely Pathogenic in the ClinVar database (Variant ID: 418295). This variant was reported among the patients for Alkaptonuria (Vilboux et al., 2009). Based on the above evidence this variant has been classified as Pathogenic according to the ACMG guidelines. -
Pathogenic, criteria provided, single submitter	clinical testing	Neuberg Centre For Genomic Medicine, NCGM	-	The observed missense c.365C>T (p.Ala122Val) variant in HGD gene has been previously reported in homozygous and compound heterozygous state in multiple individuals affected with Alkaptonuria (Khalil R et al. 2021; Danda S et al. 2020). The variant was segregated with the disease in affected family members. Experimental evidence suggests that this variant has 58% residual activity compared to the wild type indicating moderately tolerable variant (Lequeue S, et al., 2022). This variant shows a founder effect in Jordanian patients and is located in a mutational hot spot. Another missense variant p.Ala122Asp has been reported at the same position (Sen Gupta PS, et al., 2021). The p.Ala122Val variant is present with allele frequency of 0.005% in gnomAD Exomes. This variant has been submitted to the ClinVar database as Likely Pathogenic/ Pathogenic (multiple submitters). Multiple lines of computational evidence (Polyphen - Damaging, SIFT - Tolerated and MutationTaster - Disease causing/) predicts conflicting evidence on protein structure and function for this variant. The reference amino acid at this position on HGD gene is predicted as conserved by GERP++ and PhyloP across 100 vertebrates.The amino acid Ala at position 122 is changed to a Val changing protein sequence and it might alter its composition and physico-chemical properties. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 01, 2023	This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 122 of the HGD protein (p.Ala122Val). This variant is present in population databases (rs544956641, gnomAD 0.04%). This missense change has been observed in individual(s) with alkaptonuria (PMID: 12501223, 19862842, 23430897, 25804398). ClinVar contains an entry for this variant (Variation ID: 188865). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt HGD protein function with a negative predictive value of 80%. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jul 07, 2021	- -
Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Jul 03, 2014	- -
Pathogenic, no assertion criteria provided	research	Department Of Human Genetics, Institute Of Clinical And Translational Research, Biomedical Research Center, Slovak Academy Of Sciences	-	The variant was originally described in AKU patient in PMID:12501223. It has been submitted to the HGD gene mutation database (http://hgddatabase.cvtisr.sk/, DB-ID: AKU_00031). -
Pathogenic, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Aug 03, 2021	- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.51

BayesDel_addAF

Pathogenic

0.31

BayesDel_noAF

Pathogenic

0.53

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.97

D;D

Eigen

Pathogenic

0.92

Eigen_PC

Pathogenic

0.91

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.96

D;D

M_CAP

Pathogenic

0.40

MetaRNN

Pathogenic

0.97

D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.1

M;.

PrimateAI

Uncertain

0.62

PROVEAN

Uncertain

-3.7

D;D

REVEL

Pathogenic

0.92

Sift

Benign

0.090

T;D

Sift4G

Uncertain

0.046

D;D

Polyphen

1.0

D;.

Vest4

0.96

MutPred

0.93

Loss of disorder (P = 0.1114);.;

MVP

0.99

MPC

0.36

ClinPred

0.86

GERP RS

5.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.88

gMVP

0.85

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