12-120727024-A-C

Variant names:

• chr12-120727024-A-C
• rs770646738
• NM_000017.4:c.47-2A>C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000017.4(ACADS):​c.47-2A>C variant causes a splice acceptor, intron change. The variant allele was found at a frequency of 0.00000274 in 1,461,836 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: ACADS NM_000017.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 6.01

Genes affected

ACADS (HGNC:90): (acyl-CoA dehydrogenase short chain) This gene encodes a tetrameric mitochondrial flavoprotein, which is a member of the acyl-CoA dehydrogenase family. This enzyme catalyzes the initial step of the mitochondrial fatty acid beta-oxidation pathway. Mutations in this gene have been associated with short-chain acyl-CoA dehydrogenase (SCAD) deficiency. Alternative splicing results in two variants which encode different isoforms. [provided by RefSeq, Oct 2014]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 10, offset of 13, new splice context is: ccggccgctctctgtcctAGggc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 12-120727024-A-C is Pathogenic according to our data. Variant chr12-120727024-A-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1415577.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ACADS	NM_000017.4	c.47-2A>C		splice_acceptor_variant, intron_variant	Intron 1 of 9	ENST00000242592.9	NP_000008.1
ACADS	NM_001302554.2	c.47-2A>C		splice_acceptor_variant, intron_variant	Intron 1 of 9		NP_001289483.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ACADS	ENST00000242592.9	c.47-2A>C		splice_acceptor_variant, intron_variant	Intron 1 of 9	1	NM_000017.4	ENSP00000242592.4
ACADS	ENST00000411593.2	c.47-2A>C		splice_acceptor_variant, intron_variant	Intron 1 of 9	2		ENSP00000401045.2
ACADS	ENST00000539690.1	n.159-2A>C		splice_acceptor_variant, intron_variant	Intron 1 of 2	2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251436 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135894

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: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461836 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727222

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: 0.00000270

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Deficiency of butyryl-CoA dehydrogenase Pathogenic:1

Sep 19, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 1415577). This variant has not been reported in the literature in individuals affected with ACADS-related conditions. This variant is present in population databases (rs770646738, gnomAD 0.0009%). This sequence change affects an acceptor splice site in intron 1 of the ACADS gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in ACADS are known to be pathogenic (PMID: 12736383, 18523805). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Benign	-0.52
CADD	Pathogenic	32
DANN	Benign	0.80
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.40
FATHMM_MKL	Uncertain	0.94	D
GERP RS		4.4

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.88
SpliceAI score (max)		0.96		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.85		Position offset: 15
DS_AL_spliceai		0.96		Position offset: 2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs770646738; hg19: chr12-121164827;