rs776172237

Variant summary

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

The NM_000183.3(HADHB):​c.254+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000819 in 1,588,062 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 Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000077 ( 0 hom. )

Consequence

HADHB
NM_000183.3 splice_donor, intron

Scores

5
1
1
Splicing: ADA: 1.000
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 9.04

Publications

1 publications found
Variant links:
Genes affected
HADHB (HGNC:4803): (hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit beta) This gene encodes the beta subunit of the mitochondrial trifunctional protein, which catalyzes the last three steps of mitochondrial beta-oxidation of long chain fatty acids. The mitochondrial membrane-bound heterocomplex is composed of four alpha and four beta subunits, with the beta subunit catalyzing the 3-ketoacyl-CoA thiolase activity. The encoded protein can also bind RNA and decreases the stability of some mRNAs. The genes of the alpha and beta subunits of the mitochondrial trifunctional protein are located adjacent to each other in the human genome in a head-to-head orientation. Mutations in this gene result in trifunctional protein deficiency. Alternatively spliced transcript variants encoding different isoforms have been described. [provided by RefSeq, Jul 2013]
HADHB Gene-Disease associations (from GenCC):
  • mitochondrial trifunctional protein deficiency
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Orphanet, ClinGen

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 0.031578947 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 2-26269998-G-A is Pathogenic according to our data. Variant chr2-26269998-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 431987.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
HADHBNM_000183.3 linkc.254+1G>A splice_donor_variant, intron_variant Intron 5 of 15 ENST00000317799.10 NP_000174.1
HADHBNM_001281512.2 linkc.210-3653G>A intron_variant Intron 4 of 14 NP_001268441.1
HADHBNM_001281513.2 linkc.188+1G>A splice_donor_variant, intron_variant Intron 6 of 16 NP_001268442.1
HADHBXM_011532803.2 linkc.254+1G>A splice_donor_variant, intron_variant Intron 5 of 15 XP_011531105.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HADHBENST00000317799.10 linkc.254+1G>A splice_donor_variant, intron_variant Intron 5 of 15 1 NM_000183.3 ENSP00000325136.5

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152164
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251420
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.0000615
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:
0.00000766
AC:
11
AN:
1435898
Hom.:
0
Cov.:
27
AF XY:
0.00000698
AC XY:
5
AN XY:
716010
show subpopulations
African (AFR)
AF:
0.0000607
AC:
2
AN:
32970
American (AMR)
AF:
0.00
AC:
0
AN:
44700
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25944
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39550
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85716
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53400
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5712
European-Non Finnish (NFE)
AF:
0.00000827
AC:
9
AN:
1088448
Other (OTH)
AF:
0.00
AC:
0
AN:
59458
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.461
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.0000131
AC:
2
AN:
152164
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74348
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41440
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5206
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Mitochondrial trifunctional protein deficiency Pathogenic:2
Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 20, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change affects a donor splice site in intron 5 of the HADHB gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened protein product. This variant is present in population databases (rs776172237, gnomAD 0.008%). Disruption of this splice site has been observed in individual(s) with HADHB-related conditions (PMID: 24379101). ClinVar contains an entry for this variant (Variation ID: 431987). Studies have shown that disruption of this splice site results in skipping of exon 5, but is expected to preserve the integrity of the reading-frame (PMID: 24379101). 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. -

Mitochondrial trifunctional protein deficiency 1 Pathogenic:1
Mar 27, 2024
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:1
Aug 17, 2018
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.254+1 G>A variant has been reported in a patient with mitochondrial trifunctional protein deficiency who harbored a missense variant on the opposite HADHB allele (in trans) (Terrone et al. 2014). The c.254+1 G>A variant destroys the canonical splice donor site in intron 5. Sequencing of the reported patient's mRNA revealed both a wild-type transcript and a transcript lacking exon 5 consistent with c.254+1 G>A causing abnormal gene splicing (Terrone et al. 2014). The c.254+1 G>A variant is not observed in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). In summary, we interpret this variant as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.50
D
BayesDel_noAF
Pathogenic
0.34
CADD
Pathogenic
34
DANN
Uncertain
0.99
Eigen
Pathogenic
1.2
Eigen_PC
Pathogenic
1.1
FATHMM_MKL
Pathogenic
0.98
D
PhyloP100
9.0
GERP RS
5.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.94
SpliceAI score (max)
0.99
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.99
Position offset: -1

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

Publications

Other links and lift over

dbSNP: rs776172237; hg19: chr2-26492866; COSMIC: COSV58546009; COSMIC: COSV58546009; API