Galactosemia: genes and variants
Galactosemia is linked to 1 analyzed protein (GALT). 36 DNA variants are known to cause it; 14 more are uncertain, and 1 of those already look disease-causing on computable evidence.
Last updated 2026-09-30. Research information, not medical advice.
Genes linked to Galactosemia
GALT: Galactose-1-phosphate uridylyltransferase
It converts galactose-1-phosphate and UDP-glucose into glucose-1-phosphate and UDP-galactose in the Leloir pathway. Biallelic deficiency causes classic galactosemia, in which dietary galactose can lead to neonatal liver failure, sepsis risk, cataracts, and long-term complications.
36 disease-causing and 14 uncertain variants in GALT are linked to Galactosemia.
Known disease-causing variants in Galactosemia
| Variant | Position | Protein part | Clinical label |
|---|---|---|---|
| GALT H132Y | 132 | Disease-causing (★★) | |
| GALT R259Q | 259 | Disease-causing (★★) | |
| GALT R259W | 259 | Disease-causing (★★) | |
| GALT M298I | 298 | Disease-causing (★★) | |
| GALT S143L | 143 | Disease-causing (★★) | |
| GALT R333Q | 333 | Disease-causing (★★) | |
| GALT R333W | 333 | Disease-causing (★★) | |
| GALT R333G | 333 | Disease-causing (★★) | |
| GALT R51Q | 51 | Disease-causing (★★) | |
| GALT V168M | 168 | Disease-causing (★★) | |
| GALT R231G | 231 | Disease-causing (★★) | |
| GALT E271D | 271 | Disease-causing (★★) | |
| GALT H319Q | 319 | Disease-causing (★★) | |
| GALT P325L | 325 | Disease-causing (★★) | |
| GALT E352Q | 352 | Disease-causing (★★) | |
| GALT R67H | 67 | Disease-causing (★★) | |
| GALT S135L | 135 | Disease-causing (★★) | |
| GALT M142K | 142 | Disease-causing (★★) | |
| GALT S143W | 143 | Disease-causing (★★) | |
| GALT F171S | 171 | Disease-causing (★★) | |
| GALT R258C | 258 | Disease-causing (★★) | |
| GALT R328C | 328 | Disease-causing (★★) | |
| GALT N97D | 97 | Disease-causing (★★) | |
| GALT R272C | 272 | Disease-causing (★★) | |
| GALT M298V | 298 | Disease-causing (★★) | |
| GALT E363K | 363 | Disease-causing (★★) | |
| GALT R148W | 148 | Disease-causing (★★) | |
| GALT K285N | 285 | Disease-causing (★★) | |
| GALT Q344K | 344 | Disease-causing (★★) | |
| GALT M1L | 1 | Disease-causing (★★) | |
| GALT V42A | 42 | Disease-causing (★★) | |
| GALT V128I | 128 | Disease-causing (★★) | |
| GALT H132Q | 132 | Disease-causing (★) | |
| GALT A330V | 330 | Disease-causing (★) | |
| GALT M336L | 336 | Disease-causing (★) | |
| GALT G179R | 179 | Disease-causing (★) |
Uncertain variants in Galactosemia that look disease-causing
| Variant | Position | Protein part | Clinical label | Evidence |
|---|---|---|---|---|
| GALT R272H | 272 | Conflicting reports (★) | +7: 2 other pathogenic changes within 3 positions; R272C at the same position is pathogenic; seen in 6.8e-06 of gnomAD DNA copies; REVEL 0.884 |
Same protein, different disease
- Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase is also caused by GALT variants; they fall partly in the same places as the Galactosemia variants (65 disease-causing).
Diseases related to Galactosemia
- Deficiency of UDPglucose-hexose-1-phosphate uridylyltransferase, also linked to GALT
- Fetal anomalies with a likely genetic cause, also linked to GALT
Frequently asked questions
Which genes are linked to Galactosemia?
In CATVariant, Galactosemia is linked to 1 analyzed protein: GALT (Galactose-1-phosphate uridylyltransferase).
How many genetic variants are linked to Galactosemia?
67 variants: 36 are classified as disease-causing (pathogenic or likely pathogenic) in ClinVar and 14 are of uncertain significance or have conflicting reports.
Which uncertain variants in Galactosemia look disease-causing?
1 uncertain variants reach the likely-pathogenic range of the ACMG/AMP points scale on computable evidence, for example GALT R272H. These are leads for expert review, not diagnoses.
About this data
Variant–disease links come from ClinVar, Open Targets and UniProt, pooled from the latest public CATVariant analysis of each human protein. Evidence scores use the ACMG/AMP Bayesian points scale with computable criteria only (position among known disease variants, rarity in gnomAD, calibrated predictors, deep mutational scanning); there is no family or patient data, so they prioritise variants for expert review and never classify them.
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