NM_000155.4:c.1057C>T

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 15 ACMG points: 15P and 0B. PVS1_StrongPM2PP3PP5_Very_Strong

The NM_000155.4(GALT):c.1057C>T(p.Gln353*) variant causes a stop gained, splice region change. The variant allele was found at a frequency of 0.000000684 in 1,461,858 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: not found (cov: 31)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

GALT
NM_000155.4 stop_gained, splice_region

Scores

Splicing: ADA: 0.9968

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 4.13

Publications

4 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

GALT links:

ENSG00000258728 (HGNC:):

ENSG00000258728 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 15 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 8 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 9-34649562-C-T is Pathogenic according to our data. Variant chr9-34649562-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 25325.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
GALT	NM_000155.4 link	c.1057C>T	p.Gln353*	stop_gained, splice_region_variant	Exon 10 of 11	ENST00000378842.8	NP_000146.2
GALT	NM_001258332.2 link	c.730C>T	p.Gln244*	stop_gained, splice_region_variant	Exon 8 of 9		NP_001245261.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GALT	ENST00000378842.8 link	c.1057C>T	p.Gln353*	stop_gained, splice_region_variant	Exon 10 of 11	1	NM_000155.4	ENSP00000368119.4
ENSG00000258728	ENST00000556278.1 link	c.432+1106C>T		intron_variant	Intron 4 of 7	5		ENSP00000451792.1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461858

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727230

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53406

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111992

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

Alfa

AF:

0.00000494

Hom.:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase

Pathogenic:3

Dec 19, 2023

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 25, 2016

Counsyl

Significance:Likely pathogenic

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. -

May 31, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Gln353*) in the GALT gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 27 amino acid(s) of the GALT protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with galactose-1-phosphate uridylyltransferase deficiency (PMID: 17486650). ClinVar contains an entry for this variant (Variation ID: 25325). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant disrupts a region of the GALT protein in which other variant(s) (p.Glu363Lys) have been determined to be pathogenic (PMID: 21150919, 30718057). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.65

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.84

FATHMM_MKL

Pathogenic

0.99

PhyloP100

4.1

Vest4

0.95

GERP RS

4.4

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.84

SpliceAI score (max)

0.52

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.52

Position offset: 2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over