14-50885769-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_001206673.2(ABHD12B):c.536T>C(p.Phe179Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000384 in 1,614,046 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.000036 (0 hom.)
• Consequence: ABHD12B NM_001206673.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.281

Genes affected

ABHD12B (HGNC:19837): (abhydrolase domain containing 12B) Predicted to enable acylglycerol lipase activity; lysophospholipase activity; and palmitoyl-(protein) hydrolase activity. Predicted to be involved in monoacylglycerol catabolic process and phosphatidylserine catabolic process. Predicted to be active in endoplasmic reticulum membrane. [provided by Alliance of Genome Resources, Apr 2022]

PYGL (HGNC:9725): (glycogen phosphorylase L) This gene encodes a homodimeric protein that catalyses the cleavage of alpha-1,4-glucosidic bonds to release glucose-1-phosphate from liver glycogen stores. This protein switches from inactive phosphorylase B to active phosphorylase A by phosphorylation of serine residue 15. Activity of this enzyme is further regulated by multiple allosteric effectors and hormonal controls. Humans have three glycogen phosphorylase genes that encode distinct isozymes that are primarily expressed in liver, brain and muscle, respectively. The liver isozyme serves the glycemic demands of the body in general while the brain and muscle isozymes supply just those tissues. In glycogen storage disease type VI, also known as Hers disease, mutations in liver glycogen phosphorylase inhibit the conversion of glycogen to glucose and results in moderate hypoglycemia, mild ketosis, growth retardation and hepatomegaly. Alternative splicing results in multiple transcript variants encoding different isoforms.[provided by RefSeq, Feb 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.3959796).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ABHD12B	NM_001206673.2	c.536T>C	p.Phe179Ser	missense_variant	7/13	ENST00000337334.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ABHD12B	ENST00000337334.7	c.536T>C	p.Phe179Ser	missense_variant	7/13	1	NM_001206673.2	P1

Frequencies

GnomAD3 genomes AF: 0.0000657 AC: 10 AN: 152158 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000966

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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: 0.0000735

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000597 AC: 15 AN: 251420 Hom.: 0 AF XY: 0.0000736 AC XY: 10 AN XY: 135882

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.0000867

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.0000462

Gnomad NFE exome AF: 0.0000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000356 AC: 52 AN: 1461888 Hom.: 0 Cov.: 31 AF XY: 0.0000316 AC XY: 23 AN XY: 727244

Gnomad4 AFR exome AF: 0.000119

Gnomad4 AMR exome AF: 0.0000671

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000374

Gnomad4 NFE exome AF: 0.0000360

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000657 AC: 10 AN: 152158 Hom.: 0 Cov.: 31 AF XY: 0.0000538 AC XY: 4 AN XY: 74332

Gnomad4 AFR AF: 0.0000966

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000735

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000434 Hom.: 0

Bravo AF: 0.0000642

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.0000494 AC: 6

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 03, 2022

The c.536T>C (p.F179S) alteration is located in exon 7 (coding exon 7) of the ABHD12B gene. This alteration results from a T to C substitution at nucleotide position 536, causing the phenylalanine (F) at amino acid position 179 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Benign	-0.0044	T
BayesDel_noAF	Uncertain	-0.050
Cadd	Uncertain	24
Dann	Uncertain	1.0
Eigen	Uncertain	0.39
Eigen_PC	Uncertain	0.33
FATHMM_MKL	Benign	0.60	D
LIST_S2	Uncertain	0.92	D;D
M_CAP	Benign	0.026	D
MetaRNN	Benign	0.40	T;T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.53	T
PROVEAN	Pathogenic	-6.3	D;D
REVEL	Uncertain	0.29
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.0020	D;D
Polyphen		0.95	P;P
Vest4		0.59
MVP		0.30
MPC		0.43
ClinPred		0.59	D
GERP RS		4.6
Varity_R		0.83
gMVP		0.84

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		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: rs145536989; hg19: chr14-51352487;