9-6610208-G-T

Variant names:

• chr9-6610208-G-T
• rs142181803
• NM_000170.3:c.619C>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_000170.3(GLDC):​c.619C>A​(p.Leu207Met) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,612,086 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L207V) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: GLDC NM_000170.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.98
• Publications: 3 publications found

Genes affected

GLDC (HGNC:4313): (glycine decarboxylase) Degradation of glycine is brought about by the glycine cleavage system, which is composed of four mitochondrial protein components: P protein (a pyridoxal phosphate-dependent glycine decarboxylase), H protein (a lipoic acid-containing protein), T protein (a tetrahydrofolate-requiring enzyme), and L protein (a lipoamide dehydrogenase). The protein encoded by this gene is the P protein, which binds to glycine and enables the methylamine group from glycine to be transferred to the T protein. Defects in this gene are a cause of nonketotic hyperglycinemia (NKH).[provided by RefSeq, Jan 2010]

GLDC Gene-Disease associations (from GenCC):

• glycine encephalopathy

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Myriad Women’s Health, Labcorp Genetics (formerly Invitae), ClinGen
• glycine encephalopathy 1

  Inheritance: AR Classification: DEFINITIVE Submitted by: G2P
• infantile glycine encephalopathy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• neonatal glycine encephalopathy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• atypical glycine encephalopathy

  Inheritance: Unknown Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 12 uncertain in NM_000170.3
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.15322515).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000170.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GLDC	NM_000170.3	MANE Select	c.619C>A	p.Leu207Met	missense	Exon 4 of 25	NP_000161.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GLDC	ENST00000321612.8	TSL:1 MANE Select	c.619C>A	p.Leu207Met	missense	Exon 4 of 25	ENSP00000370737.4
	GLDC	ENST00000639840.1	TSL:5	c.325C>A	p.Leu109Met	missense	Exon 3 of 5	ENSP00000491161.1
	GLDC	ENST00000639364.1	TSL:5	n.319C>A		non_coding_transcript_exon	Exon 3 of 24

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152234 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000482

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459852 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 725952

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44470

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26062

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39670

South Asian (SAS) AF: 0.00 AC: 0 AN: 85680

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53334

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111098

Other (OTH) AF: 0.00 AC: 0 AN: 60300

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152234 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74370

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000482 AC: 2 AN: 41464

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5194

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10630

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68048

Other (OTH) AF: 0.00 AC: 0 AN: 2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000203476), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.076
BayesDel_addAF	Uncertain	0.037	T
BayesDel_noAF	Benign	-0.18
CADD	Benign	15
DANN	Benign	0.10
DEOGEN2	Benign	0.33	T
Eigen	Benign	-0.83
Eigen_PC	Benign	-0.54
FATHMM_MKL	Benign	0.47	N
LIST_S2	Benign	0.79	T
M_CAP	Benign	0.074	D
MetaRNN	Benign	0.15	T
MetaSVM	Uncertain	-0.26	T
MutationAssessor	Benign	-1.5	N
PhyloP100		6.0
PrimateAI	Uncertain	0.50	T
PROVEAN	Benign	1.2	N
REVEL	Uncertain	0.36
Sift	Benign	1.0	T
Sift4G	Benign	1.0	T
Polyphen		0.0010	B
Vest4		0.38
MutPred		0.68		Gain of MoRF binding (P = 0.0718)
MVP		0.73
MPC		0.045
ClinPred		0.27	T
GERP RS		4.4
Varity_R		0.25
gMVP		0.74
Mutation Taster		=67/33	polymorphism

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: rs142181803; hg19: chr9-6610208;