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Genetics Library / Genes / GALT

GENE REFERENCE / HGNC:4135

GALT

galactose-1-phosphate uridylyltransferase

protein-coding gene9p13.3Gene information

What does this gene do?

The GALT gene provides instructions for making an enzyme called galactose-1-phosphate uridylyltransferase. This enzyme enables the body to process a simple sugar called galactose, which is present in small amounts in many foods. Galactose is primarily part of a larger sugar called lactose, which is found in all dairy products and many baby formulas.

Galactose-1-phosphate uridylyltransferase is responsible for one step in a chemical process that breaks down galactose into other molecules that can be used by the body. Specifically, this enzyme converts a modified form of galactose (galactose-1-phosphate) to glucose, which is another simple sugar. Glucose is the main energy source for most cells. This chemical reaction also produces another form of galactose (UDP-galactose) that is used to build galactose-containing proteins and fats. These modified proteins and fats play critical roles in chemical signaling, building cellular structures, transporting molecules, and producing energy.

Source: MedlinePlus, National Library of Medicine. Source publication: 2020-08-18. Source review: 2008-01.

Related condition topics

MedlinePlus mentions this gene in the condition pages below. These links alone do not show that the gene causes a condition.

ClinGen reviews

We found no matching ClinGen review in the data used here. This does not rule out a link between the gene and a condition.

ClinVar records

These numbers show what has been submitted to ClinVar. They cannot tell you how likely you are to have a condition.

Submitted alleles
1,084
Submissions for variants in or overlapping this gene
2,331
Submissions explicitly reporting this gene
2,233
Alleles reported pathogenic / likely pathogenic
344
VariationIDs with uncertain significance
260
VariationIDs with conflicting classifications
85

The rows count different things: alleles, submissions or VariationIDs. Their categories can overlap, so do not add them together. Pathogenic/likely pathogenic counts exclude structural variants that merely overlap a gene. A dash in the source means “not reported,” not zero.

NCBI produces the gene-summary file each week using counts recorded at the start of the month. The numbers may differ from those on the live ClinVar website. Read the field definitions ↗

View this gene in ClinVar ↗

YOUR DNA FILE

Can your DNA file tell you about GALT?

From a DNA test kit (such as 23andMe, AncestryDNA or MyHeritage). These kits check a fixed list of about 600,000 to 700,000 positions across your whole genome. ClinVar lists 344 alleles in GALT reported as pathogenic or likely pathogenic. A kit checks only some of these positions, and often none of them.

From whole genome sequencing (a VCF file). Sequencing reads most of your genome. Your file lists the places where your DNA differs from the reference genome. Some regions are hard to sequence, including parts of some genes that have near-identical copies elsewhere, and a VCF file does not record which positions were read well.

If a variant is not in your file, that does not mean you don’t have it.

What BioDecode checks

BioDecode compares every variant in your file with ClinVar, on your own computer. For each match, it shows the ClinVar classification, the review status and the condition it was reported for. Your file is not uploaded.

A ClinVar classification applies to one particular variant and the condition it was reported for. It does not tell you about other variants in GALT.

BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.

Sources and dates

The source information on this page last changed on 2026-10-31.

HGNC Source details

Open source record ↗

Source release: Fri, 30 Oct 2026 14:04:30 GMT
Source record updated: 2026-10-22

SHA-256: f820c1457459821a6319541b4f2c407ad7c8423cd854b5bd00915d86baec4fb1

MedlinePlus Source details

Open source record ↗

Source release: Sat, 31 Oct 2026 05:16:00 GMT
Source publication: 2020-08-18
Source review: 2008-01

SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a

ClinVar Source details

Open source record ↗

Source release: Sun, 25 Oct 2026 02:34:50 GMT

SHA-256: 7c4667b67e9e2e34ae6b73f11a35f4952bd416d5eb4f342636808a6d78e88bef

About the library sources · Latest validated release · Record 9b05e0aaf4e2