rs587777604

chr20-25317064-C-Gchr20-25317064-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001042472.3(ABHD12):c.557G>C(p.Arg186Pro) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,460,288 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. R186C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: ABHD12 NM_001042472.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity no assertion criteria provided P:1 U:1
• Conservation: PhyloP100: 6.38

Genes affected

ABHD12 (HGNC:15868): (abhydrolase domain containing 12, lysophospholipase) This gene encodes an enzyme that catalyzes the hydrolysis of 2-arachidonoyl glycerol (2-AG), the main endocannabinoid lipid transmitter that acts on cannabinoid receptors, CB1 and CB2. The endocannabinoid system is involved in a wide range of physiological processes, including neurotransmission, mood, appetite, pain appreciation, addiction behavior, and inflammation. Mutations in this gene are associated with the neurodegenerative disease, PHARC (polyneuropathy, hearing loss, ataxia, retinitis pigmentosa, and cataract), resulting from an inborn error of endocannabinoid metabolism. Alternatively spliced transcript variants encoding different isoforms have been noted for this gene.[provided by RefSeq, Jan 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.875

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ABHD12	NM_001042472.3	c.557G>C	p.Arg186Pro	missense_variant	5/13	ENST00000339157.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ABHD12	ENST00000339157.10	c.557G>C	p.Arg186Pro	missense_variant	5/13	2	NM_001042472.3	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460288 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726386

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: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: no assertion criteria provided

Submissions by phenotype

PHARC syndrome Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Aug 01, 2014

- -

Cone dystrophy Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Sep 01, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.21
Cadd	Pathogenic	29
Dann	Uncertain	0.99
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D;D;D;D
M_CAP	Benign	0.045	D
MetaRNN	Pathogenic	0.88	D;D;D;D;D
MetaSVM	Uncertain	-0.099	T
MutationAssessor	Pathogenic	3.3	M;M;.;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-6.9	D;D;.;.;D
REVEL	Pathogenic	0.83
Sift	Pathogenic	0.0	D;D;.;.;D
Sift4G	Pathogenic	0.0	D;D;.;.;D
Polyphen		0.097	B;D;.;.;D
Vest4		0.99
MutPred		0.70		Loss of methylation at R186 (P = 0.0306);Loss of methylation at R186 (P = 0.0306);.;.;.;
MVP		0.59
MPC		0.69
ClinPred		1.0	D
GERP RS		4.2
Varity_R		0.99
gMVP		0.97

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: rs587777604; hg19: chr20-25297700;