rs786204589

Positions:

• chr2-26193667-CAT-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000182.5(HADHA):​c.1793_1794delAT​(p.His598fs) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000394 in 152,312 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000015 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: HADHA NM_000182.5 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 7.87

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]

GAREM2 (HGNC:27172): (GRB2 associated regulator of MAPK1 subtype 2)

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-26193667-CAT-C is Pathogenic according to our data. Variant chr2-26193667-CAT-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 188962.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
HADHA	NM_000182.5	c.1793_1794delAT	p.His598fs	frameshift_variant	17/20	ENST00000380649.8	NP_000173.2
GAREM2	XM_011532567.4	c.1683+6353_1683+6354delAT		intron_variant			XP_011530869.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
HADHA	ENST00000380649.8	c.1793_1794delAT	p.His598fs	frameshift_variant	17/20	1	NM_000182.5	ENSP00000370023.3

Frequencies

GnomAD3 genomes AF: 0.0000394 AC: 6 AN: 152194 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000482

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000414

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000278 AC: 7 AN: 251486 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135916

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000145

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.0000151 AC: 22 AN: 1461752 Hom.: 0 AF XY: 0.00000963 AC XY: 7 AN XY: 727186

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.000134

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000108

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000394 AC: 6 AN: 152312 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74482

Gnomad4 AFR AF: 0.0000481

Gnomad4 AMR AF: 0.0000653

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000414

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000340

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Likely pathogenic, criteria provided, single submitter	literature only	Counsyl	Sep 10, 2014	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Mar 26, 2024	- -

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Feb 01, 2022	PM2, PS3_supporting, PVS1 -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Apr 09, 2020	Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at a significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 11855930, 29519241, 31980526, 12442268, 12971428, 31589614, 32778825) -

Long chain 3-hydroxyacyl-CoA dehydrogenase deficiency;CN376812:Mitochondrial trifunctional protein deficiency 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

New York Genome Center

Sep 23, 2022

The homozygous c.1793_1794del, p.(His598ArgfsTer33) variant identified in the HADHA gene is a deletion of two nucleotides in exon# 17 of this 20-exon gene which alters the wild-type translational reading frame and is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. This variant is found with low frequency in population databases gnomADv2.1.1, gnomADv3.1.2, TOPMed Freeze 8 (21 out of 590,312 heterozygous alleles, no homozygotes) suggesting it is not a common benign variant in the populations represented in those databases. This variant is reported as Pathogenic / Likely Pathogenic in ClinVar (Variation ID: 188962) and has been reported as homozygous in at least two unrelated infants affected with HADHA-related disorders [PMID: 29519241, 11855930]; a newborn with severe cardiomyopathy at first day of life who died of lactic acidosis at 4 days old [PMID: 29519241], and in another newborn with mitochondrial TFP deficiency [PMID: 11855930]. Given its deleterious nature, low frequency in population databases, and prior observation as homozygous in apparently unrelated affected neonates in the literature, the homozygous c.1793_1794del, p.(His598ArgfsTer33) variant identified in the HADHA gene is reported here as Pathogenic. -

Mitochondrial trifunctional protein deficiency 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center

Dec 18, 2024

- -

Mitochondrial trifunctional protein deficiency Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Oct 17, 2021

Variant summary: HADHA c.1793_1794delAT (p.His598ArgfsX33) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 2.8e-05 in 251486 control chromosomes (gnomAD). c.1793_1794delAT has been reported in the literature in individuals affected with Mitochondrial trifunctional protein deficiency (MTFP); in a homozygous patient with maternal uniparental disomy for chromosome 2 (Hintz 2002, Spiekerkoetter 2002) and in two other patients, where one of them was a confirmed homozygote (Lee 2003, Kang 2018). These data indicate that the variant is likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on enzyme activity in cultured fibroblasts which revealed marked deficiencies in both LCHAD and LKAT activities, consistent with complete TFP deficiency. Acylcarnitine analysis of a blood spot from the original newborn screening card was also consistent with the established diagnosis (Hintz 2002). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

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

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 01, 2023

This sequence change creates a premature translational stop signal (p.His598Argfs*33) in the HADHA gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in HADHA are known to be pathogenic (PMID: 7738175, 21103935, 21549624, 22459206). This variant is present in population databases (rs769580842, gnomAD 0.01%). This premature translational stop signal has been observed in individual(s) with mitochondrial trifunctional protein deficiency (PMID: 11855930). This variant is also known as 1793-94delAT, R593ter. ClinVar contains an entry for this variant (Variation ID: 188962). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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

LitVar

Other links and lift over

dbSNP: rs769580842; hg19: chr2-26416536;