Presenters: PICU/AO1 UNIT Moderators: Dr Somwe Dr Mwenechanya GALACTOSEMIA Presenters: PICU/AO1 UNIT Moderators: Dr Somwe Dr Mwenechanya

Introduction Galactosemia is a an autosomal recessive disorder in which galactose is not properly metabolized Dietary lactose is broken down by lactase into glucose and galactose and then in a 3 step process galactose is converted to glucose This metabolic pathway is important for the newborn whose main carbohydrate source is lactose

Cont… Classic galactosemia, involves a deficiency of galactose-1-phosphate uridyl transferase This results in the buildup of galactose-1-phosphate and other precursors, causing damage to many organs including the liver, kidneys, ocular lens, cardiac muscles, brain, gonadal tissues and erythrocytes

Cont… The earlier the disorder is diagnosed and a galactose free diet is implemented, the less damage will ensue Developmental delays and learning disabilities are common even with optimal dietary treatment Incidence is 1:60000

Cont…

Pathophysiology Galactosemia is associated with 3 enzyme deficiencies Galactokinase which converts galactose to galactose-1-phosphate Uridine diphosphate (UDP) galactose-4-epimerase epimerizes UDP galactose to UDP glucose

Cont… Galactose-1-phosphate uridyl transferase converts galactose-1-phosphate and UDP glucose to UDP galactose and glucose-1-phosphate

Leloir pathway of galactose metabolism

Types TYPE LOCUS ENZYME NAME TYPE I 9p13 Galactose-1-phosphate uridyl transferase Classic galactocaemia Type 2 17q24 galactokinase Galactokinase deficiency Type 3 1p36-p35 UDP galactose epimerase Galactose epimerase deficiency

Clinical features Poor growth within the 1st few weeks of life Feeding difficulties Seizures Jaundice Hepatomegaly Splenomegaly E coli sepsis cataracts

Investigations Newborn screening Urine: Non-glucose reducing substances Enzyme assay in red blood cells Liver function tests serum glucose level Liver function test Blood culture

Treatment Lactose and galactose free diet Infants can be fed with; Soy formula Meat based formula Lactose free formula

Prognosis If untreated, severe classic galactocaemia is a life threatening disorder Babies who get an early diagnosis and strictly avoid milk and milk products live a relatively normal life Mild intellectual impairment may develop even in people who avoid galactose

Complications Cataracts Cirrhosis Death(if there is galactose in the diet) Delayed speech development Ovarian failure in females Mental retardation Tremors and uncontrollable motor function

Patient education Dietary therapy requires both parental and patient education Children need to be involved in dietary management as soon as is appropriate

THANK YOU