rs111033701

Variant names:

• chr9-34647906-T-C
• rs111033701
• NM_000155.4:c.452T>C

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1 PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_000155.4(GALT):​c.452T>C​(p.Val151Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GALT NM_000155.4 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3 U:1
• Conservation: PhyloP100: 5.40
• Publications: 6 publications found

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

ENSG00000258728 (HGNC:):

ACMG classification

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, 3 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, 0.99
• PP5: Variant 9-34647906-T-C is Pathogenic according to our data. Variant chr9-34647906-T-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 25180.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	c.452T>C	p.Val151Ala	missense_variant	Exon 5 of 11	ENST00000378842.8	NP_000146.2
GALT	NM_001258332.2	c.125T>C	p.Val42Ala	missense_variant	Exon 3 of 9		NP_001245261.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GALT	ENST00000378842.8	c.452T>C	p.Val151Ala	missense_variant	Exon 5 of 11	1	NM_000155.4	ENSP00000368119.4
ENSG00000258728	ENST00000556278.1	c.253-209T>C		intron_variant	Intron 2 of 7	5		ENSP00000451792.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase Pathogenic:1 Uncertain:1

May 30, 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. -

Jul 13, 2021

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: GALT c.452T>C (p.Val151Ala) 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 was absent in 251486 control chromosomes. c.452T>C has been reported in the literature in individuals affected with Galactosemia (e.g. Elsas_1995, Kozak_2000, Yuzyuk_2018). These data indicate that the variant is likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity (e.g. Fridovich-Keil_1995, Riehman_2001, Yuzyuk_2018). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as pathogenic, and one laboratory classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as pathogenic. -

not specified Pathogenic:1

Dec 29, 2016

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Galactosemia Pathogenic:1

Mar 17, 2017

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.53
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	.;D
Eigen	Uncertain	0.59
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.89	D;D
M_CAP	Pathogenic	0.35	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	2.9	.;M
PhyloP100		5.4
PrimateAI	Benign	0.42	T
PROVEAN	Uncertain	-3.9	D;D
REVEL	Pathogenic	0.77
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.025	D;D
Polyphen		0.70	.;P
Vest4		0.85
MutPred		0.90		.;Gain of catalytic residue at V151 (P = 0.2657);
MVP		0.99
MPC		1.6
ClinPred		0.99	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.91
gMVP		0.91
Mutation Taster		=52/48	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs111033701; hg19: chr9-34647903;