rs111033665

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1PM2PM5PP2PP3_StrongPP5

The NM_000155.4(GALT):​c.241G>A​(p.Ala81Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,780 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A81P) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

GALT
NM_000155.4 missense

Scores

9
4
4

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1

Conservation

PhyloP100: 9.20

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 12 ACMG points.

PM1
In a hotspot region, there are 4 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;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr9-34647247-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1330596.
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, 0.951
PP5
Variant 9-34647247-G-A is Pathogenic according to our data. Variant chr9-34647247-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 25141.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000155.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
GALT
NM_000155.4
MANE Select
c.241G>Ap.Ala81Thr
missense
Exon 2 of 11NP_000146.2
GALT
NM_001258332.2
c.39G>Ap.Glu13Glu
synonymous
Exon 2 of 9NP_001245261.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
GALT
ENST00000378842.8
TSL:1 MANE Select
c.241G>Ap.Ala81Thr
missense
Exon 2 of 11ENSP00000368119.4
ENSG00000258728
ENST00000556278.1
TSL:5
c.241G>Ap.Ala81Thr
missense
Exon 2 of 8ENSP00000451792.1
GALT
ENST00000450095.6
TSL:2
c.39G>Ap.Glu13Glu
synonymous
Exon 2 of 9ENSP00000401956.2

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461780
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
727176
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:
26134
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:
53358
Middle Eastern (MID)
AF:
0.000347
AC:
2
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111970
Other (OTH)
AF:
0.00
AC:
0
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.00
Hom.:
0

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase Pathogenic:1
Dec 25, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 81 of the GALT protein (p.Ala81Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of galactosemia and/or galactose-1-phosphate uridylyltransferase deficiency (PMID: 1427861; Invitae). ClinVar contains an entry for this variant (Variation ID: 25141). 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 80%. This variant disrupts the p.Ala81 amino acid residue in GALT. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 31194895). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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.

not provided Uncertain:1
Sep 18, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
BayesDel_addAF
Pathogenic
0.54
D
BayesDel_noAF
Pathogenic
0.53
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.78
D
Eigen
Uncertain
0.65
Eigen_PC
Pathogenic
0.67
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
D
M_CAP
Pathogenic
0.31
D
MetaRNN
Pathogenic
0.95
D
MetaSVM
Pathogenic
1.1
D
PhyloP100
9.2
PrimateAI
Uncertain
0.60
T
PROVEAN
Benign
-1.8
N
REVEL
Pathogenic
0.85
Sift
Benign
0.050
D
Sift4G
Benign
0.16
T
Polyphen
0.74
P
Vest4
0.59
MutPred
0.85
Gain of catalytic residue at A81 (P = 0.0864)
MVP
0.99
MPC
1.7
ClinPred
0.98
D
GERP RS
5.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.54
gMVP
0.79
Mutation Taster
=7/93
disease causing

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: rs111033665; hg19: chr9-34647244; API