rs786205088

chr2-26238933-C-T

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1 PM2 PP3_Strong PP5_Very_Strong

The NM_000182.5(HADHA):c.180+1G>A variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000315 in 1,584,870 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 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: HADHA NM_000182.5 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 7.52

Genes affected

HADHA (HGNC:4801): (hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit alpha) This gene encodes the alpha 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 alpha subunit catalyzing the 3-hydroxyacyl-CoA dehydrogenase and enoyl-CoA hydratase activities. Mutations in this gene result in trifunctional protein deficiency or LCHAD deficiency. 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. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 22 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 2-26238933-C-T is Pathogenic according to our data. Variant chr2-26238933-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 8730.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HADHA	NM_000182.5	c.180+1G>A		splice_donor_variant		ENST00000380649.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HADHA	ENST00000380649.8	c.180+1G>A		splice_donor_variant		1	NM_000182.5	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152188 Hom.: 0 Cov.: 33

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000279 AC: 4 AN: 1432682 Hom.: 0 Cov.: 28 AF XY: 0.00000280 AC XY: 2 AN XY: 714582

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: 0.0000117

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000276

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152188 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74354

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Long chain 3-hydroxyacyl-CoA dehydrogenase deficiency Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Feb 08, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Oct 12, 2023	- -

Mitochondrial trifunctional protein deficiency Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	OMIM	May 01, 1995	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jun 14, 2019	Variant summary: HADHA c.180+1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a 5' splicing donor site. Two predict the variant abolishes a 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 251376 control chromosomes (gnomAD). c.180+1G>A has been reported in the literature in at least one individual affected with Mitochondrial trifunctional protein deficiency with deletion of exon 3 of HADHA cDNA (Brackett_1995, Ibdah_1999). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. A ClinVar submission from a clinical diagnostic laboratory (evaluation after 2014) cite the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Mitochondrial trifunctional protein deficiency;C3711645:Long chain 3-hydroxyacyl-CoA dehydrogenase deficiency Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Aug 09, 2023

This sequence change affects a donor splice site in intron 3 of the HADHA gene. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or disrupted protein product. This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with mitochondrial trifunctional protein deficiency (PMID: 7738175). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 8730). Studies have shown that disruption of this splice site results in skipping of exon 3 and introduces a premature termination codon (PMID: 7738175). The resulting mRNA is expected to undergo nonsense-mediated decay. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
Cadd	Pathogenic	32
Dann	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	D;D
GERP RS		6.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.8

Splicing

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

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

Publications

LitVar

Other links and lift over

dbSNP: rs786205088; hg19: chr2-26461801;