rs1553316176

Variant names:

• chr2-26239138-TA-T
• rs1553316176
• NM_000182.5:c.72delT

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_000182.5(HADHA):​c.72delT​(p.Tyr24fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000207 in 1,448,506 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: HADHA NM_000182.5 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 1.07

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 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-26239138-TA-T is Pathogenic according to our data. Variant chr2-26239138-TA-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 552438.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
HADHA	NM_000182.5	c.72delT	p.Tyr24fs	frameshift_variant	Exon 2 of 20	ENST00000380649.8	NP_000173.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HADHA	ENST00000380649.8	c.72delT	p.Tyr24fs	frameshift_variant	Exon 2 of 20	1	NM_000182.5	ENSP00000370023.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251002 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135778

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 SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000207 AC: 3 AN: 1448506 Hom.: 0 Cov.: 28 AF XY: 0.00000416 AC XY: 3 AN XY: 721582

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: 0.0000349

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Jul 17, 2023

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Likely pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with LCHAD deficiency, (MIM#609016) and mitochondrial trifunctional protein (TFP) deficiency (MIM#609015). (I) 0106 - This gene is associated with autosomal recessive disease. There is currently no genotype-phenotype correlation distinguishing LCHAD and TFP deficiency; enzymatic assay will be required. (I) 0204 - Variant is predicted to result in a truncated protein (premature termination codon is located within the first 102 nucleotides of the coding sequence and is predicted to escape nonsense-mediated decay). (SP) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD <0.01 for a recessive condition (v2: 1 heterozygote, 0 homozygotes). (SP) 0704 - Another predicted 5’ NMD-escape variant comparable to the one identified in this case has limited previous evidence for pathogenicity (ClinVar). (SP) 0802 - This variant has moderate previous evidence of pathogenicity in unrelated individuals. It has been reported as likely pathogenic and pathogenic by diagnostic laboratories in ClinVar. One of these laboratories identified this variant in their carrier screening test (personal communication). (SP) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1102 - Strong phenotype match for this individual. (SP) 1206 - This variant has been shown to be paternally inherited (by segregation analysis). (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Jun 09, 2017

Counsyl

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 29, 2018

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: HADHA c.72delT (p.Tyr24X) 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 (eg. p.R291X and p.L656X). The variant allele was found at a frequency of 4.1e-06 in 246080 control chromosomes in gnomAD, which does not exceed the maximal expected allele frequency for a pathogenic variant in HADHA. The variant c.72delT has been reported in the literature in individuals affected with Long Chain 3-Hydroxyacyl-CoA Dehydrogenase Deficiency (SPIEKERKOETTER_2004). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined here, the variant was classified as likely pathogenic. -

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

Jan 31, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1

Nov 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

HADHA: PVS1, PM2, PM3:Supporting -

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

Oct 04, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Tyr24*) 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 not present in population databases (ExAC no frequency). This premature translational stop signal has been observed in individual(s) with mitochondrial trifunctional protein deficiency (PMID: 14630990). ClinVar contains an entry for this variant (Variation ID: 552438). 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: rs1553316176; hg19: chr2-26462006;