NM_000155.4:c.667C>T

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP5

The NM_000155.4(GALT):c.667C>T(p.Arg223Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000266 in 1,613,998 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000025 ( 0 hom. )

Consequence

GALT
NM_000155.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:3

Conservation

PhyloP100: 3.14

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]

GALT links:

ENSG00000258728 (HGNC:):

ENSG00000258728 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 9-34648436-C-T is Pathogenic according to our data. Variant chr9-34648436-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 529225.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1, Pathogenic=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GALT	NM_000155.4 link	c.667C>T	p.Arg223Cys	missense_variant	Exon 7 of 11	ENST00000378842.8	NP_000146.2	P07902-1B2RAT6A0A0S2Z3Y7
GALT	NM_001258332.2 link	c.340C>T	p.Arg114Cys	missense_variant	Exon 5 of 9		NP_001245261.1	P07902-2B2RAT6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GALT	ENST00000378842.8 link	c.667C>T	p.Arg223Cys	missense_variant	Exon 7 of 11	1	NM_000155.4	ENSP00000368119.4		P07902-1
ENSG00000258728	ENST00000556278.1 link	c.412C>T	p.Arg138Cys	missense_variant	Exon 4 of 8	5		ENSP00000451792.1		G3V4G9

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152126

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.0000735

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.0000278

AC:

AN:

251460

Hom.:

AF XY:

0.0000294

AC XY:

AN XY:

135910

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.000139

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000246

AC:

AN:

1461872

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

727236

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.0000749

Gnomad4 NFE exome

AF:

0.0000225

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000460

AC:

AN:

152126

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74314

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.000478

Alfa

AF:

0.0000844

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3Uncertain:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase

Pathogenic:2

Jul 01, 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 223 of the GALT protein (p.Arg223Cys). This variant is present in population databases (rs111033750, gnomAD 0.008%). This missense change has been observed in individual(s) with galactose-1-phosphate uridylyltransferase deficiency (Invitae). ClinVar contains an entry for this variant (Variation ID: 529225). 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 GALT protein function with a positive predictive value of 95%. This variant disrupts the p.Arg223 amino acid residue in GALT. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 17876724, 22461411). 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 16, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Premature ovarian failure

Pathogenic:1

Mar 02, 2020

Medical Cytogenetics and Molecular Genetics Laboratory, IRCCS Istituto Auxologico Italiano

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

GALT-related disorder

Uncertain:1

Feb 03, 2024

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The GALT c.667C>T variant is predicted to result in the amino acid substitution p.Arg223Cys. This variant was reported in the heterozygous state without a second GALT variant in an individual with primary ovarian insufficiency (described as c.C304T, p.R114C in Bestetti et al. 2021. PubMed ID: 34480478). We have observed this variant along with the Duarte variant in an individual with an abnormal newborn screen for galactosemia (PreventionGenetics internal data). Additionally, a different substitution of the same amino acid (p.Arg223Ser) was reported along with a known pathogenic GALT variant in a study of individuals with abnormal newborn screening results for galactosemia (Calderon et al. 2007. PubMed ID: 17876724). This variant is reported in 0.012% of alleles in individuals of European (Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/9-34648433-C-T). Although we suspect this variant may be pathogenic, at this time its clinical significance is uncertain due to the absence of conclusive functional and genetic evidence. -

Galactosemia

Uncertain:1

Jan 03, 2019

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not provided

Uncertain:1

Jun 19, 2018

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.16

BayesDel_addAF

Pathogenic

0.27

BayesDel_noAF

Pathogenic

0.25

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.93

.;D;.

Eigen

Benign

0.13

Eigen_PC

Benign

0.044

FATHMM_MKL

Uncertain

0.87

LIST_S2

Benign

0.84

T;T;T

M_CAP

Pathogenic

0.79

MetaRNN

Uncertain

0.69

D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Uncertain

2.7

.;M;.

PrimateAI

Benign

0.25

PROVEAN

Uncertain

-4.3

D;D;D

REVEL

Pathogenic

0.69

Sift

Uncertain

0.0020

D;D;D

Sift4G

Uncertain

0.022

D;D;D

Polyphen

0.99

.;D;.

Vest4

0.46

MVP

1.0

MPC

1.9

ClinPred

0.80

GERP RS

3.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.53

gMVP

0.82

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over