Clinical Guidance

The neonatal period. Infants with Duarte galactosemia demonstrate no higher prevalence of acute complications in infancy than controls, regardless of whether they consume breast milk, a dairy milk-based formula, or a low-galactose formula . Note: For any infant, resolution of clinical manifestations following the removal of breast milk or dairy milk-based formula from the diet does not confirm that the clinical manifestations were related to dietary galactose. Neurodevelopment. A study reported 73 outcomes representing five general domains of development (cognitive, physical, motor, socioemotional, and speech/language) in 350 children (206 with Duarte galactosemia and 144 controls) .

Diagnostic Criteria

Suggestive Findings

Duarte galactosemia should be suspected in an infant with an for galactosemia OR a and family history; clinical findings are not present even when on a high-galactose diet (e.g., breast milk or a dairy milk-based formula).

Infant with Out-of-Range NBS Result

NBS for classic galactosemia and its variants (including Duarte galactosemia) is primarily based on the use of dried blood spots collected between 24 and 72 hours after birth to quantify erythrocyte galactose-1-phosphate uridylyltransferase (GALT) enzyme activity and/or galactose metabolites.

Management Guidelines

Evaluations Following Initial Diagnosis

An infant with a confirmed diagnosis of Duarte galactosemia who presents with concerning clinical manifestations should be referred to a metabolic specialist for evaluation of another concurrent condition, since infants with Duarte galactosemia do not have clinical features of a biochemical disorder. Consultation with a certified genetic counselor to obtain a pedigree and inform individuals with Duarte galactosemia and their families about the nature, mode of inheritance, and genetic implications of a diagnosis of Duarte galactosemia is recommended.

Surveillance Guidelines

Although most metabolic specialists surveyed report that no surveillance of infants with Duarte galactosemia is needed [JL Fridovich-Keil RH Singh, personal observations], some infants with Duarte galactosemia who are given a galactose-restricted diet and followed by a genetics or metabolic specialist are discharged from follow up after a successful galactose challenge at age one year . Among children with Duarte galactosemia who experienced dietary galactose restriction in infancy, if the erythrocyte galactose-1-phosphate concentration is 1.0 mg/dL following a galactose challenge at age one year, galactose restriction may be resumed, and the galactose challenge and measurement of erythrocyte galactose-1-phosphate concentration repeated every four to six months until the erythrocyte galactose-1-phosphate concentration stabilizes at 1.0 mg/dL. If the erythrocyte galactose-1-phosphate concentration continues to rise to 1.0 mg/dL following a galactose challenge, it may be appropriate to reconsider if the diagnosis of Duarte galactosemia is correct, or if another concurrent condition is present.