1-75734832-GAAGT-G

Position:

• chr1-75734832-GAAGT-G

Variant summary

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

The NM_000016.6(ACADM):​c.431_434delAGTA​(p.Lys144fs) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,686 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ACADM NM_000016.6 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 9.10

Genes affected

ACADM (HGNC:89): (acyl-CoA dehydrogenase medium chain) This gene encodes the medium-chain specific (C4 to C12 straight chain) acyl-Coenzyme A dehydrogenase. The homotetramer enzyme catalyzes the initial step of the mitochondrial fatty acid beta-oxidation pathway. Defects in this gene cause medium-chain acyl-CoA dehydrogenase deficiency, a disease characterized by hepatic dysfunction, fasting hypoglycemia, and encephalopathy, which can result in infantile death. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ACADM (HGNC:):

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 1-75734832-GAAGT-G is Pathogenic according to our data. Variant chr1-75734832-GAAGT-G is described in ClinVar as [Pathogenic]. Clinvar id is 371546.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
ACADM	NM_000016.6	c.431_434delAGTA	p.Lys144fs	frameshift_variant	6/12	ENST00000370841.9	NP_000007.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ACADM	ENST00000370841.9	c.431_434delAGTA	p.Lys144fs	frameshift_variant	6/12	1	NM_000016.6	ENSP00000359878.5

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461686 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 727152

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 30

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Medium-chain acyl-coenzyme A dehydrogenase deficiency Pathogenic:5

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Sep 26, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 08, 2018	Variant summary: ACADM c.431_434delAGTA (p.Lys144IlefsX5) 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/likely pathogenic by our laboratory (eg. c.999_1011dupTAGAATGAGTTAC, p.Gln338X; c.1114dupG, p.Ala372fsX11). The variant was absent in 118778 control chromosomes (ExAC). The c.431_434delAGTA has been reported in the literature in multiple individuals affected with Medium Chain Acyl-CoA Dehydrogenase Deficiency, including two homozygotes (Catarzi_2013, McKinney_2004, Ali_2011, Arnold_2010, Zhao_2017). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence confirming elevated blood acylcarnitines levels in patients with this variant (Catarzi_2013). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Oct 14, 2016	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Feb 11, 2022	For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 371546). This premature translational stop signal has been observed in individual(s) with proven or suspected medium-chain acyl-coenzyme A dehydrogenase deficiency (PMID: 15171998, 24294134). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Lys144Ilefs*5) in the ACADM gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ACADM are known to be pathogenic (PMID: 16121256, 20434380). -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jun 01, 2017

The c.431_434delAGTA variant in the ACADM gene has been reported previously in association with medium chain acyl-CoA dehydrogenase (MCAD) deficiency (McKinney et al., 2004; Ali et al., 2011). The deletion causes a frameshift starting with codon Lysine 144, changes this amino acid to an Isoleucine residue and creates a premature Stop codon at position 5 of the new reading frame, denoted p.Lys144IlefsX5. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The c.431_434delAGTA 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 c.431_434delAGTA as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.15		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: rs1057517356; hg19: chr1-76200517;