Galactokinase deficiency

Galactokinase deficiency is an inborn error of galactose metabolism. Untreated patients develop early onset, bilateral cataracts, which at this time appears to be the only consistent abnormality in galactokinase deficiency. Rarely, additional clinical symptoms have been reported including asymptomatic hypoglycemia, mental retardation, failure to thrive, seizures, deafness, hepatomegaly, and hypercholesterolemia; however, it is unclear whether these additional abnormalities are a result of galactokinase enzyme deficiency. In one report of 18 affected patients, the authors report that additional symptoms seemed to be more prevalent in patients who were non-compliant with treatment. Treatment of patients with a lactose-free, reduced galactose diet results in prevention or, in some cases, regression of cataracts. Estimates of the frequency of galactokinase deficiency range from 1 in 2,200,00 to 1 in 40,000.1 The highest incidence has been found in the Romani population where the carrier frequency is estimated to be 1 in 47.

Tests Available

Forms and Documents

Test Details

  • Confirmation of biochemical diagnosis
  • Carrier testing


4-5 weeks
2-5 mL Blood - Lavender Top Tube
Buccal Swabs

*Reporting times are typical, but could be extended in situations outside GeneDx's reasonable control.


  • 796.6 Abnormal findings on neonatal screening
  • 366.44 Cataract associated with other syndromes, Code first underlying condition, as: craniofacial dysostosis (756.0) galactosemia (271.1)
  • 271.1 Galactosemia, Galactose-1-phosphate uridyl transferase deficiency, Galactosuria
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**The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.


  1. Hennermann et al., (2011) J Inherit Metab Dis Feb 3. [Epub ahead of print].
  2. Bosch et al., (2002) J Inherit Metab Dis 25:629-634.
  3. Hunter et al., (2002) Pediatr Res 51:602-6.
  4. Hunter et al., (2001) Hum Mutat 17:77-8.
  5. Kolosha et al., (2000) Hum Mutat 15:447-453.
  6. Asada et al., (1999) J Hum Genet 44:377-382.
  7. Park et al., (2007) Mol Genet Metab 91:234-238.
  8. Park et al., (2009) BMC Med Genet 10:29.