9-6606627-G-T

Variant names:

• chr9-6606627-G-T
• rs12006003
• NM_000170.3:c.678C>A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_000170.3(GLDC):​c.678C>A​(p.His226Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000206 in 1,457,464 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 Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. H226H) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: GLDC NM_000170.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.17
• 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: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.965

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GLDC	NM_000170.3	MANE Select	c.678C>A	p.His226Gln	missense	Exon 5 of 25	NP_000161.2	P23378

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GLDC	ENST00000321612.8	TSL:1 MANE Select	c.678C>A	p.His226Gln	missense	Exon 5 of 25	ENSP00000370737.4	P23378
	GLDC	ENST00000920236.1		c.678C>A	p.His226Gln	missense	Exon 5 of 25	ENSP00000590295.1
	GLDC	ENST00000953081.1		c.678C>A	p.His226Gln	missense	Exon 5 of 26	ENSP00000623139.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251490 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000867

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1457464 Hom.: 0 Cov.: 28 AF XY: 0.00000138 AC XY: 1 AN XY: 725444

African (AFR) AF: 0.00 AC: 0 AN: 33206

American (AMR) AF: 0.0000671 AC: 3 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26112

East Asian (EAS) AF: 0.00 AC: 0 AN: 39686

South Asian (SAS) AF: 0.00 AC: 0 AN: 86168

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1108128

Other (OTH) AF: 0.00 AC: 0 AN: 60260

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Glycine encephalopathy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.49
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.86	D
Eigen	Uncertain	0.58
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.64	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.3	H
PhyloP100		1.2
PrimateAI	Uncertain	0.53	T
PROVEAN	Pathogenic	-6.5	D
REVEL	Pathogenic	0.92
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0070	D
Polyphen		1.0	D
Vest4		0.85
MutPred		0.83		Loss of catalytic residue at H226 (P = 0.0577)
MVP		0.99
MPC		0.30
ClinPred		1.0	D
GERP RS		2.3
Varity_R		0.98
gMVP		0.93
Mutation Taster		=39/61	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
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

Other links and lift over

dbSNP: rs12006003; hg19: chr9-6606627;