chr3-120644419-C-G

Variant names:

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.674G>C(p.Arg225Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,614,090 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. R225C) has been classified as Likely pathogenic.

Frequency

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

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

HGD
NM_000187.4 missense

Scores

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 7.38

Publications

8 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

HGD links:

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 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 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 chr3-120644420-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1512988.

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 3-120644419-C-G is Pathogenic according to our data. Variant chr3-120644419-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2627692.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
HGD	NM_000187.4 link	c.674G>C	p.Arg225Pro	missense_variant	Exon 10 of 14	ENST00000283871.10	NP_000178.2	Q93099

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
HGD	ENST00000283871.10 link	c.674G>C	p.Arg225Pro	missense_variant	Exon 10 of 14	1	NM_000187.4	ENSP00000283871.5	Q93099
HGD	ENST00000494453.1 link	c.92G>C	p.Arg31Pro	missense_variant	Exon 2 of 5	3		ENSP00000419163.1	H7C576
HGD	ENST00000475447.2 link	c.200+179G>C		intron_variant	Intron 3 of 4	3		ENSP00000417977.2	H7C4R8
HGD	ENST00000492108.5 link	n.180+2554G>C		intron_variant	Intron 3 of 5	2		ENSP00000419838.1	H7C5G7

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152150

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

GnomAD2 exomes

AF:

0.00000399

AC:

AN:

250868

AF XY:

0.00000738

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000410

AC:

AN:

1461822

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727220

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.0000580

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53394

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111978

Other (OTH)

AF:

0.00

AC:

AN:

60390

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.442

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.00000657

AC:

AN:

152268

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74464

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41542

American (AMR)

AF:

0.00

AC:

AN:

15298

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5180

South Asian (SAS)

AF:

0.000207

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68028

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.675

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Alkaptonuria

Pathogenic:3

Feb 07, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

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 patients in PMID: 25681086. It has been submitted to the HGD gene mutation database (http://hgddatabase.cvtisr.sk/, DB-ID: AKU_00AKU_00170). -

Dec 08, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.Arg225 amino acid residue in HGD. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 12872836, 25681086). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. This missense change has been observed in individuals with Alkaptonuria (PMID: 25681086). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 225 of the HGD protein (p.Arg225Pro). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.53

BayesDel_noAF

Pathogenic

0.53

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.99

Eigen

Pathogenic

0.75

Eigen_PC

Pathogenic

0.76

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.99

M_CAP

Pathogenic

0.44

MetaRNN

Pathogenic

0.98

MetaSVM

Uncertain

0.49

MutationAssessor

Pathogenic

3.5

PhyloP100

7.4

PrimateAI

Uncertain

0.72

PROVEAN

Pathogenic

-6.2

REVEL

Pathogenic

0.96

Sift

Uncertain

0.0040

Sift4G

Uncertain

0.0040

Polyphen

0.99

Vest4

0.99

MutPred

0.91

Gain of glycosylation at R225 (P = 0.0643);

MVP

0.95

MPC

0.58

ClinPred

1.0

GERP RS

6.0

Varity_R

0.99

gMVP

0.97

Mutation Taster

=0/100

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over