19-12891930-A-G

Variant names:

• chr19-12891930-A-G
• rs748185335
• NM_000159.4:c.227A>G

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_000159.4(GCDH):​c.227A>G​(p.Gln76Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,886 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q76P) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: GCDH NM_000159.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.76
• Publications: 1 publications found

Genes affected

GCDH (HGNC:4189): (glutaryl-CoA dehydrogenase) The protein encoded by this gene belongs to the acyl-CoA dehydrogenase family. It catalyzes the oxidative decarboxylation of glutaryl-CoA to crotonyl-CoA and CO(2) in the degradative pathway of L-lysine, L-hydroxylysine, and L-tryptophan metabolism. It uses electron transfer flavoprotein as its electron acceptor. The enzyme exists in the mitochondrial matrix as a homotetramer of 45-kD subunits. Mutations in this gene result in the metabolic disorder glutaric aciduria type 1, which is also known as glutaric acidemia type I. Alternative splicing of this gene results in multiple transcript variants. A related pseudogene has been identified on chromosome 12. [provided by RefSeq, Mar 2013]

GCDH Gene-Disease associations (from GenCC):

• glutaryl-CoA dehydrogenase deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet, G2P, Myriad Women’s Health

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 11 uncertain in NM_000159.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.805

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GCDH	NM_000159.4	c.227A>G	p.Gln76Arg	missense_variant	Exon 4 of 12	ENST00000222214.10	NP_000150.1
GCDH	NM_013976.5	c.227A>G	p.Gln76Arg	missense_variant	Exon 4 of 12		NP_039663.1
GCDH	NR_102316.1	n.335A>G		non_coding_transcript_exon_variant	Exon 4 of 12
GCDH	NR_102317.1	n.643A>G		non_coding_transcript_exon_variant	Exon 3 of 11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GCDH	ENST00000222214.10	c.227A>G	p.Gln76Arg	missense_variant	Exon 4 of 12	1	NM_000159.4	ENSP00000222214.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461886 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727246

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

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

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1112004

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Glutaric aciduria, type 1 Uncertain:1

Aug 20, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamine, which is neutral and polar, with arginine, which is basic and polar, at codon 76 of the GCDH protein (p.Gln76Arg). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with GCDH-related conditions. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt GCDH protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.082
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.95	D;.;D;D;D
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.96	.;D;D;D;D
M_CAP	Pathogenic	0.54	D
MetaRNN	Pathogenic	0.80	D;D;D;D;D
MetaSVM	Pathogenic	0.92	D
MutationAssessor	Benign	1.9	M;.;M;.;.
PhyloP100		8.8
PrimateAI	Uncertain	0.54	T
PROVEAN	Uncertain	-3.5	D;.;.;.;.
REVEL	Pathogenic	0.72
Sift	Uncertain	0.029	D;.;.;.;.
Sift4G	Benign	0.095	T;D;T;T;D
Polyphen		0.0020	B;.;B;.;.
Vest4		0.61
MutPred		0.48		Gain of MoRF binding (P = 0.0378);Gain of MoRF binding (P = 0.0378);Gain of MoRF binding (P = 0.0378);.;Gain of MoRF binding (P = 0.0378);
MVP		0.95
MPC		0.94
ClinPred		0.99	D
GERP RS		5.2
Varity_R		0.67
gMVP		0.76
Mutation Taster		=8/92	disease causing

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: rs748185335; hg19: chr19-13002744;