rs367543262

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.857A>G​(p.Tyr286Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,168 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

GALT
NM_000155.4 missense

Scores

15
3
1

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:2U:1

Conservation

PhyloP100: 8.43

Publications

5 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 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 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, 0.991
PP5
Variant 9-34649034-A-G is Pathogenic according to our data. Variant chr9-34649034-A-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 38486.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.857A>G p.Tyr286Cys missense_variant Exon 9 of 11 ENST00000378842.8 NP_000146.2
GALTNM_001258332.2 linkc.530A>G p.Tyr177Cys missense_variant Exon 7 of 9 NP_001245261.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GALTENST00000378842.8 linkc.857A>G p.Tyr286Cys missense_variant Exon 9 of 11 1 NM_000155.4 ENSP00000368119.4
ENSG00000258728ENST00000556278.1 linkc.432+578A>G intron_variant Intron 4 of 7 5 ENSP00000451792.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152168
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
Cov.:
32
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152168
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74330
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41428
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.675
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000385
Hom.:
0

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:2Uncertain:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase Pathogenic:2Uncertain:1
Sep 26, 2024
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.857A>G (p.Tyr286Cys) results in a non-conservative amino acid change located in the Galactose-1-phosphate uridyl transferase, C-terminal domain (IPR005850) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251490 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.857A>G has been reported in the presumed compound heterozygous state in the literature in at least 1 individual affected with Galactosemia (example, Zaffanello_2005). These data do not allow any conclusion about variant significance. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity in patient erythrocytes (example, Zaffanello_2005). The following publication has been ascertained in the context of this evaluation (PMID: 15775761). ClinVar contains an entry for this variant (Variation ID: 38486). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Jun 14, 2017
Counsyl
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Feb 01, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 286 of the GALT protein (p.Tyr286Cys). This variant is present in population databases (rs367543262, gnomAD 0.06%). This missense change has been observed in individual(s) with galactosemia (PMID: 15775761). ClinVar contains an entry for this variant (Variation ID: 38486). 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%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.89
BayesDel_addAF
Pathogenic
0.59
D
BayesDel_noAF
Pathogenic
0.61
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.98
.;D
Eigen
Pathogenic
0.84
Eigen_PC
Pathogenic
0.77
FATHMM_MKL
Uncertain
0.97
D
LIST_S2
Pathogenic
1.0
D;D
M_CAP
Pathogenic
0.67
D
MetaRNN
Pathogenic
0.99
D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.4
.;M
PhyloP100
8.4
PrimateAI
Pathogenic
0.86
D
PROVEAN
Pathogenic
-8.9
D;D
REVEL
Pathogenic
0.98
Sift
Pathogenic
0.0
D;D
Sift4G
Uncertain
0.035
D;D
Polyphen
1.0
.;D
Vest4
0.94
MutPred
0.95
.;Gain of methylation at K285 (P = 0.0128);
MVP
1.0
MPC
2.1
ClinPred
1.0
D
GERP RS
5.7
Varity_R
0.97
gMVP
0.98
Mutation Taster
=3/97
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.10
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: rs367543262; hg19: chr9-34649031; API