rs111033734

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1PM2PM5PP3_ModeratePP5

The NM_000155.4(GALT):c.575G>A(p.Ser192Asn) variant causes a missense change. The variant allele was found at a frequency of 0.00000248 in 1,614,078 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. S192G) has been classified as Likely pathogenic.

Frequency

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

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

GALT
NM_000155.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 5.02

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

PM1

In a hotspot region, there are 12 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 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 chrnull-null-null-null is described in UniProt as null.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.916

PP5

Variant 9-34648344-G-A is Pathogenic according to our data. Variant chr9-34648344-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 25220.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GALT	NM_000155.4 linkuse as main transcript	c.575G>A	p.Ser192Asn	missense_variant	7/11	ENST00000378842.8
GALT	NM_001258332.2 linkuse as main transcript	c.248G>A	p.Ser83Asn	missense_variant	5/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GALT	ENST00000378842.8 linkuse as main transcript	c.575G>A	p.Ser192Asn	missense_variant	7/11	1	NM_000155.4	P1	P07902-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152210

Hom.:

Cov.:

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461868

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727236

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:

0.00000270

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152210

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74362

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

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

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Dec 31, 2023

This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 192 of the GALT protein (p.Ser192Asn). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with galactosemia (PMID: 7887416; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 25220). 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%. For these reasons, this variant has been classified as Pathogenic. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Aug 28, 2023

Identified in an individual with positive newborn screening for galactosemia (Elsas LJ et al., 1995); In silico analysis supports that this missense variant does not alter protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 20008339, 7887416) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.62

BayesDel_addAF

Pathogenic

0.20

BayesDel_noAF

Uncertain

0.050

Cadd

Pathogenic

Dann

Benign

0.94

Eigen

Uncertain

0.33

Eigen_PC

Uncertain

0.41

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Pathogenic

0.98

D;D;D

M_CAP

Uncertain

0.18

MetaRNN

Pathogenic

0.92

D;D;D

MetaSVM

Pathogenic

1.1

MutationTaster

Benign

1.0

A;A

PrimateAI

Uncertain

0.61

PROVEAN

Benign

-0.35

N;N;N

REVEL

Pathogenic

0.67

Sift

Benign

1.0

T;T;T

Sift4G

Benign

0.57

T;T;T

Polyphen

0.96

.;D;.

Vest4

0.88

MutPred

0.89

.;Loss of disorder (P = 0.0921);.;

MVP

0.98

MPC

1.6

ClinPred

0.90

GERP RS

4.8

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.73

gMVP

0.98

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over