chr9-34649506-A-G

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM2PP2PP3_StrongPP5_Very_Strong

The NM_000155.4(GALT):​c.1001A>G​(p.Lys334Arg) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 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 Likely pathogenic (★★).

Frequency

Genomes: not found (cov: 31)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

GALT
NM_000155.4 missense

Scores

15
3
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 4.84

Publications

7 publications found
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 Gene-Disease associations (from GenCC):
  • classic galactosemia
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet
  • galactosemia
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, Myriad Women’s Health

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 17 ACMG points.

PM1
In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_000155.4
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 104 curated pathogenic missense variants (we use a threshold of 10). The gene has 17 curated benign missense variants. Gene score misZ: 0.91493 (below the threshold of 3.09). Trascript score misZ: 1.8645 (below the threshold of 3.09). GenCC associations: The gene is linked to galactosemia, classic galactosemia.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.982
PP5
Variant 9-34649506-A-G is Pathogenic according to our data. Variant chr9-34649506-A-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 1691431.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.1001A>G p.Lys334Arg missense_variant Exon 10 of 11 ENST00000378842.8 NP_000146.2 P07902-1B2RAT6A0A0S2Z3Y7
GALTNM_001258332.2 linkc.674A>G p.Lys225Arg missense_variant Exon 8 of 9 NP_001245261.1 P07902-2B2RAT6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GALTENST00000378842.8 linkc.1001A>G p.Lys334Arg missense_variant Exon 10 of 11 1 NM_000155.4 ENSP00000368119.4 P07902-1
ENSG00000258728ENST00000556278.1 linkc.432+1050A>G intron_variant Intron 4 of 7 5 ENSP00000451792.1 G3V4G9

Frequencies

GnomAD3 genomes
Cov.:
31
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251482
AF XY:
0.00000736
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461886
Hom.:
0
Cov.:
31
AF XY:
0.00000138
AC XY:
1
AN XY:
727244
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53418
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112006
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
31
Alfa
AF:
0.00000988
Hom.:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase Pathogenic:3
Sep 08, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

For these reasons, this variant has been classified as Pathogenic. 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. ClinVar contains an entry for this variant (Variation ID: 1691431). This missense change has been observed in individual(s) with galactose-1-phosphate uridylyltransferase deficiency (PMID: 1427861, 20863731). This variant is present in population databases (rs111033809, gnomAD 0.0009%). This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 334 of the GALT protein (p.Lys334Arg). -

Mar 29, 2024
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 29, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: GALT c.1001A>G (p.Lys334Arg) results in a conservative amino acid change located in the Galactose-1-phosphate uridyl transferase, C-terminal domain (IPR005850) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251482 control chromosomes. c.1001A>G has been reported in the literature in compound heterozygous individuals affected with Galactosemia (Li_2011, Leslie_1992, Demirbas_2019). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 30718057, 1427861, 20863731). ClinVar contains an entry for this variant (Variation ID: 1691431). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

not provided Pathogenic:1
Jun 18, 2021
Mayo Clinic Laboratories, Mayo Clinic
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PS3, PS4_moderate, PM2, PP3, PP4 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.79
BayesDel_addAF
Pathogenic
0.56
D
BayesDel_noAF
Pathogenic
0.56
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.97
.;D
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.89
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
1.0
D;D
M_CAP
Pathogenic
0.80
D
MetaRNN
Pathogenic
0.98
D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
4.4
.;H
PhyloP100
4.8
PrimateAI
Uncertain
0.78
T
PROVEAN
Uncertain
-2.9
D;D
REVEL
Pathogenic
0.98
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
.;D
Vest4
0.87
MutPred
0.88
.;Loss of methylation at K334 (P = 0.0145);
MVP
0.99
MPC
0.31
ClinPred
1.0
D
GERP RS
5.2
Varity_R
0.96
gMVP
0.87
Mutation Taster
=13/87
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs111033809; hg19: chr9-34649503; API