NM_000016.6:c.503A>C

Variant names:

• chr1-75740014-A-C
• rs745844469
• NM_000016.6:c.503A>C

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_000016.6(ACADM):​c.503A>C​(p.Asp168Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000992 in 1,612,820 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D168G) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000096 (0 hom.)
• Consequence: ACADM NM_000016.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:5 U:2
• Conservation: PhyloP100: 9.18
• Publications: 6 publications found

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 Gene-Disease associations (from GenCC):

• medium chain acyl-CoA dehydrogenase deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, PanelApp Australia, ClinGen, Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in NM_000016.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-75740014-A-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 835112.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 95 curated pathogenic missense variants (we use a threshold of 10). The gene has 29 curated benign missense variants. Gene score misZ: 0.54287 (below the threshold of 3.09). Trascript score misZ: 0.41658 (below the threshold of 3.09). GenCC associations: The gene is linked to medium chain acyl-CoA dehydrogenase deficiency.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.995
• PP5: Variant 1-75740014-A-C is Pathogenic according to our data. Variant chr1-75740014-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 226072.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ACADM	NM_000016.6	c.503A>C	p.Asp168Ala	missense_variant	Exon 7 of 12	ENST00000370841.9	NP_000007.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ACADM	ENST00000370841.9	c.503A>C	p.Asp168Ala	missense_variant	Exon 7 of 12	1	NM_000016.6	ENSP00000359878.5

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152216 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

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: 0.0000159 AC: 4 AN: 251296 AF XY: 0.0000294

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000264

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000959 AC: 14 AN: 1460604 Hom.: 0 Cov.: 30 AF XY: 0.0000124 AC XY: 9 AN XY: 726678

African (AFR) AF: 0.00 AC: 0 AN: 33446

American (AMR) AF: 0.0000224 AC: 1 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26112

East Asian (EAS) AF: 0.00 AC: 0 AN: 39568

South Asian (SAS) AF: 0.00 AC: 0 AN: 86224

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53350

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.0000108 AC: 12 AN: 1111096

Other (OTH) AF: 0.0000166 AC: 1 AN: 60330

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152216 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74364

African (AFR) AF: 0.00 AC: 0 AN: 41466

American (AMR) AF: 0.0000654 AC: 1 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.0000267 Hom.: 0

Bravo AF: 0.0000302

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:5 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Medium-chain acyl-coenzyme A dehydrogenase deficiency Pathogenic:3 Uncertain:2

May 02, 2017

Counsyl

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Dec 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with alanine, which is neutral and non-polar, at codon 168 of the ACADM protein (p.Asp168Ala). This variant is present in population databases (rs745844469, gnomAD 0.002%). This missense change has been observed in individual(s) with clinical features of medium-chain acyl-coenzyme A dehydrogenase deficiency (PMID: 21083904; internal data). 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: 226072). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt ACADM protein function with a positive predictive value of 80%. This variant disrupts the p.Asp168 amino acid residue in ACADM. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 23829193; internal data). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Feb 20, 2015

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 22, 2024

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 11, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1

Nov 09, 2023

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported previously in infants with a positive newborn screen for medium chain acyl-CoA dehydrogenase (MCAD) deficiency who were also heterozygous for the common p.(K329E) pathogenic variant, although the phase of these variants was not determined (PMID: 21083904, 23543005); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 23543005, 35629059, 35281663, 21083904) -

ACADM-related disorder Pathogenic:1

Jan 10, 2024

PreventionGenetics, part of Exact Sciences

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The ACADM c.503A>C variant is predicted to result in the amino acid substitution p.Asp168Ala. This variant was reported in the compound heterozygous state with the common pathogenic c.985A>G variant in a single medium chain acyl-CoA deficiency (MCADD) patient (Kennedy et al. 2010. PubMed ID: 21083904). Notably, a different substitution of the same amino acid (c.503A>T, p.Asp168Val) in trans (on the opposite allele) with the pathogenic c.985A>G variant has also been identified in one MCADD patient (Ventura et al. 2014. PubMed ID: 23829193). Additionally, we have observed the c.503A>C (p.Asp168Ala) variant along with a second pathogenic ACADM variant in several patients with suspected MCADD, and in one of the individuals it was proven by family studies to be in trans with the other ACADM variant (PreventionGenetics internal data). The c.503A>C variant has only been observed in only 4 of ~251,000 alleles (0.0016%), indicating it is a rare variant (http://gnomad.broadinstitute.org/variant/1-76205699-A-C). Based on these observations, this variant is interpreted as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	28
DANN	Benign	0.91
DEOGEN2	Pathogenic	0.84	D;D;D;.
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D;D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.99	D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.1	.;M;.;.
PhyloP100		9.2
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-7.4	D;D;D;D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	D;D;D;D
Vest4		0.98
MutPred		0.95		.;.;Loss of ubiquitination at K206 (P = 0.0834);.;
MVP		1.0
MPC		0.83
ClinPred		1.0	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.97
gMVP		0.95
Mutation Taster		=7/93	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs745844469; hg19: chr1-76205699;