9-34648436-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1PM2PP5

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

6
7
6

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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PM1
In a helix (size 11) in uniprot entity GALT_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_000155.4
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: {Uncertain_significance=1, Pathogenic=2}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
GALTNM_000155.4 linkuse as main transcriptc.667C>T p.Arg223Cys missense_variant 7/11 ENST00000378842.8 NP_000146.2 P07902-1B2RAT6A0A0S2Z3Y7
GALTNM_001258332.2 linkuse as main transcriptc.340C>T p.Arg114Cys missense_variant 5/9 NP_001245261.1 P07902-2B2RAT6

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
GALTENST00000378842.8 linkuse as main transcriptc.667C>T p.Arg223Cys missense_variant 7/111 NM_000155.4 ENSP00000368119.4 P07902-1
ENSG00000258728ENST00000556278.1 linkuse as main transcriptc.412C>T p.Arg138Cys missense_variant 4/85 ENSP00000451792.1 G3V4G9

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152126
Hom.:
0
Cov.:
32
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:
7
AN:
251460
Hom.:
0
AF XY:
0.0000294
AC XY:
4
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:
36
AN:
1461872
Hom.:
0
Cov.:
33
AF XY:
0.0000220
AC XY:
16
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:
7
AN:
152126
Hom.:
0
Cov.:
32
AF XY:
0.0000538
AC XY:
4
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.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.0000247
AC:
3

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
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpOct 17, 2023This 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. 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. -
Likely pathogenic, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsMay 16, 2024- -
Premature ovarian failure Pathogenic:1
Pathogenic, criteria provided, single submitterresearchMedical Cytogenetics and Molecular Genetics Laboratory, IRCCS Istituto Auxologico ItalianoMar 02, 2020- -
GALT-related disorder Uncertain:1
Uncertain significance, no assertion criteria providedclinical testingPreventionGenetics, part of Exact SciencesFeb 03, 2024The 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
Uncertain significance, no assertion criteria providedclinical testingNatera, Inc.Jan 03, 2019- -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Jun 19, 2018- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
BayesDel_addAF
Pathogenic
0.27
D
BayesDel_noAF
Pathogenic
0.25
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.93
.;D;.
Eigen
Benign
0.13
Eigen_PC
Benign
0.044
FATHMM_MKL
Uncertain
0.87
D
LIST_S2
Benign
0.84
T;T;T
M_CAP
Pathogenic
0.79
D
MetaRNN
Uncertain
0.69
D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Uncertain
2.7
.;M;.
PrimateAI
Benign
0.25
T
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
D
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.

Other links and lift over

dbSNP: rs111033750; hg19: chr9-34648433; API