rs397515347

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1_ModeratePM2PP5_Very_Strong

The NM_000187.4(HGD):​c.16-1G>A variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.0000205 in 1,612,206 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

HGD
NM_000187.4 splice_acceptor, intron

Scores

4
2
1
Splicing: ADA: 1.000
2

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:10O:1

Conservation

PhyloP100: 6.85

Publications

3 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 12 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.05381166 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 3-120675864-C-T is Pathogenic according to our data. Variant chr3-120675864-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 3170.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.16-1G>A splice_acceptor_variant, intron_variant Intron 1 of 13 ENST00000283871.10 NP_000178.2 Q93099

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HGDENST00000283871.10 linkc.16-1G>A splice_acceptor_variant, intron_variant Intron 1 of 13 1 NM_000187.4 ENSP00000283871.5 Q93099

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152182
Hom.:
0
Cov.:
33
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:
0.0000882
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000199
AC:
5
AN:
251028
AF XY:
0.0000221
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:
0.0000441
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000185
AC:
27
AN:
1460024
Hom.:
0
Cov.:
30
AF XY:
0.0000206
AC XY:
15
AN XY:
726460
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33394
American (AMR)
AF:
0.00
AC:
0
AN:
44690
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26102
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39678
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86228
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5760
European-Non Finnish (NFE)
AF:
0.0000225
AC:
25
AN:
1110436
Other (OTH)
AF:
0.0000332
AC:
2
AN:
60322
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.479
Heterozygous variant carriers
0
2
3
5
6
8
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000394
AC:
6
AN:
152182
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41434
American (AMR)
AF:
0.00
AC:
0
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000882
AC:
6
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000431
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.0000247
AC:
3
EpiCase
AF:
0.0000546
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:10Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Alkaptonuria Pathogenic:8Other:1
-
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:10482952. It has been submitted to the HGD gene mutation database (http://hgddatabase.cvtisr.sk/, DB-ID: AKU_00004). -

Sep 01, 1999
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Oct 27, 2020
Breakthrough Genomics, Breakthrough Genomics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant lies in the essential splice acceptor site, in intron 1 of the HGD gene. In-silico splice prediction tools (ASSP and NNSPLICE) suggest that this variant might affect splicing due to the loss of constitutive splice site and introduction of a new splice site, which in turn might lead to a frameshift and consequent premature termination of the protein; this will likely result in loss-of-function. The variant was previously reported in patients diagnosed with alkaptonuria [PMID: 10205262, 25681086, 10482952, 23430897, 20301627]. Loss-of-function variants in HGD are known to be pathogenic [PMID: 12501223, 19862842]. -

Feb 02, 2023
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.16-1G>A variant in HGD has been reported in at least 10 individuals with alkaptonuria, several of whom were compound heterozgyous for the variant with a second pathogenic or likely pathogenic variant (Beltrán-Valero de Bernabé 1999 PMID: 1020526,Müller 1999 PMID: 10482952, Phornphutkul 2002 PMID: 1250122, Vilboux 2009 PMID: 19862842). It has also been identified in 0.009% (6/68042) of European chromosomes by gnomAD (http://gnomad.broadinstitute.org), and has been reported in ClinVar as Pathogenic by multiple submitters (ClinVar ID 3170). This variant occurs within the canonical splice site (+/- 1,2) and is predicted to cause altered splicing leading to an abnormal or absent protein. Loss of function of the HGD gene is an established disease mechanism in autosomal recessive alkaptonuria. In summary, this variant meets criteria to be classifed as pathogenic for autosomal recessive alkaptonuria. ACMG/AMP criteria applied: PM3_VeryStrong, PVS1_Moderate, PM2_Supporting. -

Dec 09, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change affects an acceptor splice site in intron 1 of the HGD gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in HGD are known to be pathogenic (PMID: 12501223, 19862842). This variant is present in population databases (rs397515347, gnomAD 0.006%). Disruption of this splice site has been observed in individuals with alkaptonuria (PMID: 10205262, 10482952, 23430897, 25681086). ClinVar contains an entry for this variant (Variation ID: 3170). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Dec 21, 2015
Counsyl
Significance: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. -

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

Frequently occurring aberrant splice variant -

Oct 01, 2021
Laboratory of Medical Genetics, National & Kapodistrian University of Athens
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PVS1, PM2, PP2, PP3, PP4, PP5 -

Feb 07, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:1
Jul 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

HGD: PM3:Very Strong, PM2, PVS1:Moderate, PP4 -

HGD-related disorder Pathogenic:1
Apr 03, 2024
PreventionGenetics, part of Exact Sciences
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

The HGD c.16-1G>A variant is predicted to disrupt the AG splice acceptor site and interfere with normal splicing. This variant has been reported in the compound heterozygous state in multiple individuals with alkaptonuria (Table 1, referred to as c.183-1G>A, Müller et al. 1999. PubMed ID: 10482952; Table 1, Beltran-Valero et al. 1999. PubMed ID: 10205262; Table 1, Usher et al. 2015. PubMed ID: 25681086). This variant is reported in 0.0044% of alleles in individuals of European (non-Finnish) descent in gnomAD. Variants that disrupt the consensus splice acceptor site in HGD are expected to be pathogenic. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.50
D
BayesDel_noAF
Pathogenic
0.32
CADD
Pathogenic
29
DANN
Uncertain
1.0
Eigen
Pathogenic
1.2
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Uncertain
0.96
D
PhyloP100
6.9
GERP RS
5.8
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.95
Splicevardb
3.0
SpliceAI score (max)
0.98
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.98
Position offset: -1

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

Publications

Other links and lift over

dbSNP: rs397515347; hg19: chr3-120394711; API