rs2296804

Positions:

• chr6-42963523-C-A
• chr6-42963523-C-G
• chr6-42963523-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_018960.6(GNMT):​c.717-12C>A variant causes a splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GNMT NM_018960.6 splice_polypyrimidine_tract, intron
• Scores: Splicing: ADA: 0.0004776
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.594

Genes affected

GNMT (HGNC:4415): (glycine N-methyltransferase) The protein encoded by this gene is an enzyme that catalyzes the conversion of S-adenosyl-L-methionine (along with glycine) to S-adenosyl-L-homocysteine and sarcosine. This protein is found in the cytoplasm and acts as a homotetramer. Defects in this gene are a cause of GNMT deficiency (hypermethioninemia). Alternative splicing results in multiple transcript variants. Naturally occurring readthrough transcription occurs between the upstream CNPY3 (canopy FGF signaling regulator 3) gene and this gene and is represented with GeneID:107080644. [provided by RefSeq, Jan 2016]

CNPY3-GNMT (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.74).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNMT	NM_018960.6	c.717-12C>A		splice_polypyrimidine_tract_variant, intron_variant		ENST00000372808.4	NP_061833.1
CNPY3-GNMT	NR_134890.2	n.579-12C>A		splice_polypyrimidine_tract_variant, intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNMT	ENST00000372808.4	c.717-12C>A		splice_polypyrimidine_tract_variant, intron_variant		1	NM_018960.6	ENSP00000361894	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 46

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.74
CADD	Benign	15
DANN	Benign	0.61

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.00048
dbscSNV1_RF	Benign	0.032
SpliceAI score (max)		0.010		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: rs2296804; hg19: chr6-42931261;