chr9-34647879-T-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong

The NM_000155.4(GALT):​c.425T>A​(p.Met142Lys) variant causes a missense change. The variant allele was found at a frequency of 0.0000155 in 1,614,190 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M142V) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

GALT
NM_000155.4 missense

Scores

15
3
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:11

Conservation

PhyloP100: 7.10
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 Pathogenic. Variant got 18 ACMG points.

PM1
In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 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 chr9-34647878-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2573375.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.991
PP5
Variant 9-34647879-T-A is Pathogenic according to our data. Variant chr9-34647879-T-A is described in ClinVar as [Pathogenic]. Clinvar id is 3609.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
GALTNM_000155.4 linkuse as main transcriptc.425T>A p.Met142Lys missense_variant 5/11 ENST00000378842.8
GALTNM_001258332.2 linkuse as main transcriptc.98T>A p.Met33Lys missense_variant 3/9

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
GALTENST00000378842.8 linkuse as main transcriptc.425T>A p.Met142Lys missense_variant 5/111 NM_000155.4 P1P07902-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152180
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:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000199
AC:
5
AN:
251496
Hom.:
0
AF XY:
0.0000221
AC XY:
3
AN XY:
135922
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:
0.00
Gnomad NFE exome
AF:
0.0000439
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000157
AC:
23
AN:
1461892
Hom.:
0
Cov.:
33
AF XY:
0.0000179
AC XY:
13
AN XY:
727246
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000198
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152298
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74478
show subpopulations
Gnomad4 AFR
AF:
0.00
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:
0.0000294
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000282
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.0000412
AC:
5

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:11
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase Pathogenic:6
Pathogenic, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsDec 02, 2021- -
Pathogenic, criteria provided, single submitterclinical testingCounsylMar 16, 2017- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJul 29, 2023This sequence change replaces methionine, which is neutral and non-polar, with lysine, which is basic and polar, at codon 142 of the GALT protein (p.Met142Lys). This variant is present in population databases (rs111033695, gnomAD 0.004%). This missense change has been observed in individual(s) with galactosemia (PMID: 2011574, 10384398, 10960497, 17041746, 20213376, 22944367, 23924834). ClinVar contains an entry for this variant (Variation ID: 3609). 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. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingBaylor Genetics-- -
Pathogenic, no assertion criteria providedliterature onlyOMIMApr 01, 1991- -
Pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpApr 23, 2021Variant summary: GALT c.425T>A (p.Met142Lys) results in a non-conservative amino acid change located in the Galactose-1-phosphate uridyl transferase, N-terminal domain of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2e-05 in 251496 control chromosomes. c.425T>A has been reported in the literature in multiple individuals affected with Galactosemia, both in the homozygous and compound heterozygous state (Reichardt_1991, Shin_1999, Milankovics_2010, Seyrantepe_1999, Bosch_2005, Gort_2006, Boutron_2012, etc). The variant has been reported to have <10% wild-type enzyme activity when expressed in COS cells (Reichardt_1991). Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
not provided Pathogenic:3
Pathogenic, criteria provided, single submitterclinical testingGeneDxMay 04, 2022Expression of M142K in COS cells was associated with a severe reduction in galactose-1-phosphate uridyltransferase (GALT) enzyme activity compared to wild type (Reichardt et al. 1991); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 22944367, 17041746, 20008339, 10960497, 20213376, 31194252, 31980526, 34030713, 31589614, 10384398, 2011574) -
Pathogenic, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Nov 14, 2013- -
Pathogenic, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenMay 01, 2024GALT: PM3:Very Strong, PM1, PM2, PM5, PP3, PS3:Supporting -
GALT-related disorder Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingPreventionGenetics, part of Exact SciencesAug 24, 2022The GALT c.425T>A variant is predicted to result in the amino acid substitution p.Met142Lys. This variant has previously been reported in the homozygous state or with a second pathogenic GALT variant in multiple patients with classic galactosemia (e.g., Reichardt et al. 1991. PubMed ID 2011574; Shin et al. 1999. PubMed ID 10384398; Boutron et al. 2012, PMID 22944367). The p.Met142Lys substitution was reported to abolish GALT enzyme activity in a functional study using COS cells (Reichardt et al. 1991. PubMed ID 2011574). This variant is reported in 0.0044% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/9-34647876-T-A). It is interpreted as a pathogenic variant but multiple independent submitters to ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/3609/). Taken together, we interpret this variant as pathogenic. -
Galactosemia Pathogenic:1
Pathogenic, no assertion criteria providedclinical testingNatera, Inc.Mar 17, 2017- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.91
BayesDel_addAF
Pathogenic
0.48
D
BayesDel_noAF
Pathogenic
0.58
CADD
Pathogenic
28
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.97
.;D
Eigen
Pathogenic
0.96
Eigen_PC
Pathogenic
0.86
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Pathogenic
0.99
D;D
M_CAP
Pathogenic
0.73
D
MetaRNN
Pathogenic
0.99
D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.6
.;H
MutationTaster
Benign
1.0
D;D
PrimateAI
Uncertain
0.70
T
PROVEAN
Pathogenic
-5.3
D;D
REVEL
Pathogenic
0.98
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
.;D
Vest4
0.96
MutPred
0.93
.;Gain of catalytic residue at M142 (P = 0.0016);
MVP
1.0
MPC
1.4
ClinPred
0.90
D
GERP RS
5.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.99
gMVP
1.0

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.17
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: rs111033695; hg19: chr9-34647876; API