NM_000155.4:c.691C>T

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The NM_000155.4(GALT):​c.691C>T​(p.Arg231Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000411 in 1,461,050 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 Likely pathogenic (★★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

GALT
NM_000155.4 missense

Scores

16
2
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 4.37
Variant links:
Genes affected
GALT (HGNC:4135): (galactose-1-phosphate uridylyltransferase) Galactose-1-phosphate uridyl transferase (GALT) catalyzes the second step of the Leloir pathway of galactose metabolism, namely the conversion of UDP-glucose + galactose-1-phosphate to glucose-1-phosphate + UDP-galactose. The absence of this enzyme results in classic galactosemia in humans and can be fatal in the newborn period if lactose is not removed from the diet. The pathophysiology of galactosemia has not been clearly defined. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Apr 2012]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.994
PP5
Variant 9-34648765-C-T is Pathogenic according to our data. Variant chr9-34648765-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 25246.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GALTNM_000155.4 linkc.691C>T p.Arg231Cys missense_variant Exon 8 of 11 ENST00000378842.8 NP_000146.2 P07902-1B2RAT6A0A0S2Z3Y7
GALTNM_001258332.2 linkc.364C>T p.Arg122Cys missense_variant Exon 6 of 9 NP_001245261.1 P07902-2B2RAT6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GALTENST00000378842.8 linkc.691C>T p.Arg231Cys missense_variant Exon 8 of 11 1 NM_000155.4 ENSP00000368119.4 P07902-1
ENSG00000258728ENST00000556278.1 linkc.432+309C>T intron_variant Intron 4 of 7 5 ENSP00000451792.1 G3V4G9

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000798
AC:
2
AN:
250552
Hom.:
0
AF XY:
0.00000738
AC XY:
1
AN XY:
135488
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.0000994
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000411
AC:
6
AN:
1461050
Hom.:
0
Cov.:
32
AF XY:
0.00000550
AC XY:
4
AN XY:
726898
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.0000383
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000180
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
Bravo
AF:
0.0000113
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase Pathogenic:5
May 07, 2024
Fulgent Genetics, Fulgent Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Nov 22, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 231 of the GALT protein (p.Arg231Cys). This variant is present in population databases (rs111033749, gnomAD 0.01%). This missense change has been observed in individual(s) with low GALT enzyme activity, findings that are highly specific for galactose-1-phosphate uridylyltransferase deficiency (PMID: 14518827, 22944367; internal data). ClinVar contains an entry for this variant (Variation ID: 25246). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt GALT protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects GALT function (PMID: 25614870, 25814382). This variant disrupts the p.Arg231 amino acid residue in GALT. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 7550229, 11152465, 22944367, 25614870). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

May 08, 2023
Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: research

- -

Jun 21, 2016
Counsyl
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Nov 14, 2016
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: The GALT c.691C>T (p.Arg231Cys) variant involves the alteration of a conserved nucleotide and is located in the intersubunit interface of the protein (Boutron_2012). 4/4 in silico tools predict a damaging outcome for this variant. This variant has been reported multiple patients with galactosemia in homozygous or compound heterozygous state with other pathogenic variants (Alfadhel_2016, Boutron_2012, Schadewaldt_2003) and is absent in 121210 control chromosomes. A functional study showed this variant leads to loss of enzymatic activity (Coelho_2014). Another missense change (p.R231H) at this residue has also been reported in association with galactosemia (ARUP, ClinVar). Multiple clinical diagnostic laboratories/reputable databases have classified this variant as pathogenic. Taken together, this variant is classified as Pathogenic. -

not provided Pathogenic:2
Feb 26, 2024
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Published functional studies found this variant is associated with significantly reduced enzyme activity (PMID: 25614870); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 27629047, 33636947, 36515074, 25614870, 22944367, 30718057, 25814382, 31980526, 31130284) -

Feb 15, 2018
Eurofins Ntd Llc (ga)
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Galactosemia Pathogenic:1
Sep 23, 2020
Natera, Inc.
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.81
BayesDel_addAF
Pathogenic
0.49
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
32
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.99
.;D
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.94
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.95
D;D
M_CAP
Pathogenic
0.79
D
MetaRNN
Pathogenic
0.99
D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
4.4
.;H
PrimateAI
Uncertain
0.63
T
PROVEAN
Pathogenic
-8.0
D;D
REVEL
Pathogenic
0.98
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
.;D
Vest4
0.96
MutPred
0.98
.;Gain of catalytic residue at L232 (P = 0.0287);
MVP
1.0
MPC
2.1
ClinPred
1.0
D
GERP RS
5.8
RBP_binding_hub_radar
0.97
RBP_regulation_power_radar
2.7
Varity_R
0.98
gMVP
0.99

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs111033749; hg19: chr9-34648762; COSMIC: COSV66592990; COSMIC: COSV66592990; API