10-87094544-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_005271.5(GLUD1):c.226C>T(p.Arg76Cys) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. R76R) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: GLUD1 NM_005271.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.11

Genes affected

GLUD1 (HGNC:4335): (glutamate dehydrogenase 1) This gene encodes glutamate dehydrogenase, which is a mitochondrial matrix enzyme that catalyzes the oxidative deamination of glutamate to alpha-ketoglutarate and ammonia. This enzyme has an important role in regulating amino acid-induced insulin secretion. It is allosterically activated by ADP and inhibited by GTP and ATP. Activating mutations in this gene are a common cause of congenital hyperinsulinism. Alternative splicing of this gene results in multiple transcript variants. The related glutamate dehydrogenase 2 gene on the human X-chromosome originated from this gene via retrotransposition and encodes a soluble form of glutamate dehydrogenase. Related pseudogenes have been identified on chromosomes 10, 18 and X. [provided by RefSeq, Jan 2016]

SHLD2 (HGNC:28773): (shieldin complex subunit 2) Involved in negative regulation of double-strand break repair via homologous recombination; positive regulation of double-strand break repair via nonhomologous end joining; and positive regulation of isotype switching. Located in nucleus and site of double-strand break. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.869

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GLUD1	NM_005271.5	c.226C>T	p.Arg76Cys	missense_variant	1/13	ENST00000277865.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GLUD1	ENST00000277865.5	c.226C>T	p.Arg76Cys	missense_variant	1/13	1	NM_005271.5	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hyperinsulinism-hyperammonemia syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Mar 31, 2020

This variant was classified as: Uncertain significance. The available evidence favors the pathogenic nature of this variant, however the currently available data is insufficient to conclusively support its pathogenic nature. Thus this variant is classified as Uncertain significance - favor pathogenic. The following ACMG criteria were applied in classifying this variant: PM2,PP2,PP3. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.83
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
Cadd	Pathogenic	33
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.80	D
Eigen	Benign	0.069
Eigen_PC	Benign	0.067
FATHMM_MKL	Benign	0.61	D
LIST_S2	Uncertain	0.92	D
M_CAP	Pathogenic	0.58	D
MetaRNN	Pathogenic	0.87	D
MetaSVM	Benign	-0.93	T
MutationAssessor	Benign	1.2	L
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.75	T
PROVEAN	Pathogenic	-5.3	D
REVEL	Pathogenic	0.77
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.79
MutPred		0.60		Loss of disorder (P = 0.0319);
MVP		0.95
MPC		2.3
ClinPred		1.0	D
GERP RS		3.0
Varity_R		0.60
gMVP		0.83

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

Publications

LitVar

Other links and lift over

dbSNP: rs1841666156; hg19: chr10-88854301;