rs120074170

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong

The NM_000187.4(HGD):​c.899T>G​(p.Val300Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000415 in 1,613,994 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V300L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000044 ( 0 hom. )

Consequence

HGD
NM_000187.4 missense

Scores

12
6
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5O:1

Conservation

PhyloP100: 8.73

Publications

11 publications found
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 Gene-Disease associations (from GenCC):
  • alkaptonuria
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 19 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 5 uncertain 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 chr3-120638563-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1939335.Status of the report is criteria_provided_single_submitter, 1 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 127 curated pathogenic missense variants (we use a threshold of 10). The gene has 16 curated benign missense variants. Gene score misZ: 0.28979 (below the threshold of 3.09). Trascript score misZ: 0.53625 (below the threshold of 3.09). GenCC associations: The gene is linked to alkaptonuria.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.984
PP5
Variant 3-120638562-A-C is Pathogenic according to our data. Variant chr3-120638562-A-C is described in ClinVar as Pathogenic. ClinVar VariationId is 3166.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HGDNM_000187.4 linkc.899T>G p.Val300Gly missense_variant Exon 12 of 14 ENST00000283871.10 NP_000178.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HGDENST00000283871.10 linkc.899T>G p.Val300Gly missense_variant Exon 12 of 14 1 NM_000187.4 ENSP00000283871.5

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152110
Hom.:
0
Cov.:
32
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.0000445
AC:
65
AN:
1461766
Hom.:
0
Cov.:
32
AF XY:
0.0000385
AC XY:
28
AN XY:
727200
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.0000540
AC:
60
AN:
1111914
Other (OTH)
AF:
0.0000662
AC:
4
AN:
60386
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.493
Heterozygous variant carriers
0
3
6
10
13
16
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152228
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74434
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41540
American (AMR)
AF:
0.00
AC:
0
AN:
15298
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5154
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4812
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68016
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000460
Hom.:
0
Bravo
AF:
0.0000264
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:5Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Alkaptonuria Pathogenic:5Other:1
Feb 01, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 300 of the HGD protein (p.Val300Gly). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with alkaptonuria (PMID: 8782815, 9529363, 10482952, 10970188, 19862842, 21720873). It is commonly reported in individuals of Central European ancestry (PMID: 9529363, 21720873). ClinVar contains an entry for this variant (Variation ID: 3166). 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 expected to disrupt HGD protein function with a positive predictive value of 80%. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. For these reasons, this variant has been classified as Pathogenic. -

-
Department Of Human Genetics, Institute Of Clinical And Translational Research, Biomedical Research Center, Slovak Academy Of Sciences
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:research

The variant was originally described in AKU patient in PMID:8782815. It has been submitted to the HGD gene mutation database (http://hgddatabase.cvtisr.sk/, DB-ID: AKU_00083). -

-
GeneReviews
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

Frequent missense variant -

Dec 18, 2015
Counsyl
Significance:Likely 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. -

Jun 02, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 01, 1996
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.95
BayesDel_addAF
Pathogenic
0.56
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
34
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.98
D
Eigen
Uncertain
0.53
Eigen_PC
Uncertain
0.47
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.97
D
M_CAP
Pathogenic
0.61
D
MetaRNN
Pathogenic
0.98
D
MetaSVM
Uncertain
0.54
D
MutationAssessor
Pathogenic
3.8
H
PhyloP100
8.7
PrimateAI
Uncertain
0.76
T
PROVEAN
Pathogenic
-6.9
D
REVEL
Pathogenic
0.97
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.87
MutPred
0.93
Loss of stability (P = 0.0025);
MVP
0.93
MPC
0.55
ClinPred
1.0
D
GERP RS
5.4
Varity_R
0.99
gMVP
0.93
Mutation Taster
=11/89
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.50
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.50
Position offset: 0

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

Publications

Other links and lift over

dbSNP: rs120074170; hg19: chr3-120357409; API