chr1-75739984-A-G

Variant names:

• chr1-75739984-A-G
• rs1553123858
• NM_000016.6:c.473A>G

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate PP5

The NM_000016.6(ACADM):​c.473A>G​(p.Tyr158Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,457,692 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. Y158H) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: ACADM NM_000016.6 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3 U:1
• Conservation: PhyloP100: 6.18
• Publications: 0 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 10 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 8 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 chr1-75739983-T-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 807358.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 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, 0.925
• PP5: Variant 1-75739984-A-G is Pathogenic according to our data. Variant chr1-75739984-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 550256.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ACADM	NM_000016.6	c.473A>G	p.Tyr158Cys	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.473A>G	p.Tyr158Cys	missense_variant	Exon 7 of 12	1	NM_000016.6	ENSP00000359878.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1457692 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 725124

African (AFR) AF: 0.00 AC: 0 AN: 33378

American (AMR) AF: 0.00 AC: 0 AN: 44542

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26018

East Asian (EAS) AF: 0.00 AC: 0 AN: 39524

South Asian (SAS) AF: 0.00 AC: 0 AN: 85568

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53208

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5752

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1109472

Other (OTH) AF: 0.00 AC: 0 AN: 60230

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Medium-chain acyl-coenzyme A dehydrogenase deficiency Pathogenic:3 Uncertain:1

May 29, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Jan 05, 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.

Jul 15, 2025

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: ACADM c.473A>G (p.Tyr158Cys) results in a non-conservative amino acid change located in the Acyl-CoA oxidase/dehydrogenase, middle domain (IPR006091) of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be disruptive. The variant was absent in 249568 control chromosomes. c.473A>G has been observed in at least one compound heterozygous individual affected with Medium Chain Acyl-CoA Dehydrogenase Deficiency (example: Derks_2008, Touw_2013, Jager_2019). At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in reduced affinity for the flavin adenine dinucleotide (FAD) cofactor and reduced catalytic activity when expressed in E. coli (Madeira_2023). Additionally, at least one missense variant at the Tyr158 residue has been reported as likely pathogenic/pathogenic in ClinVar (c.472T>C/p.Tyr158His), suggesting this codon could be critical for normal function of the protein. The following publications have been ascertained in the context of this evaluation (PMID: 18188679, 31012112, 37257730, 23509891). ClinVar contains an entry for this variant (Variation ID: 550256). Based on the evidence outlined above, the variant was classified as likely pathogenic.

Oct 01, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 158 of the ACADM protein (p.Tyr158Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency (PMID: 23509891, 31012112). ClinVar contains an entry for this variant (Variation ID: 550256). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt ACADM protein function. This variant disrupts the p.Tyr158 amino acid residue in ACADM. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 19224950, 24718418). 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.

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.86
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.30
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.80	D;D;D;.
Eigen	Uncertain	0.58
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.95	D;D;D;D
M_CAP	Pathogenic	0.67	D
MetaRNN	Pathogenic	0.92	D;D;D;D
MetaSVM	Pathogenic	0.85	D
MutationAssessor	Benign	0.0	.;M;.;.
PhyloP100		6.2
PrimateAI	Uncertain	0.71	T
PROVEAN	Pathogenic	-8.4	D;D;D;D
REVEL	Pathogenic	0.83
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Vest4		0.63
ClinPred		1.0	D
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.97
gMVP		0.90
Mutation Taster		=27/73	disease causing

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: rs1553123858; hg19: chr1-76205669;