Table 4.

Red flags suggestive of inborn errors of metabolism

• Family history of IEM or developmental disorder or unexplained neonatal or sudden infant death

• Consanguinity

• Intrauterine growth retardation

• Failure to thrive

• Head circumference or stature growth abnormality (>2 SD above or under the mean)

• Recurrent episodes of vomiting, ataxia, seizures, lethargy, coma

• History of being severely symptomatic and needing longer to recover with benign illnesses (e.g., upper respiratory tract infection)

• Unusual dietary preferences (e.g., protein or carbohydrate aversion)

• Regression in developmental milestones

• Behavioural or psychiatric problems (e.g., psychosis at a young age)

• Movement disorder (e.g., dystonia)

• Facial dysmorphism (e.g., coarse facial features)

• Organomegaly

• Severe hypotonia

• Congenital nonfacial anomalies

• Sensory deficits, especially if progressive (e.g., cataracts, retinopathy)

• Noncongenital progressive spine deformities

• Neuro-imaging abnormalities

Data taken from ref. (5).

IEM Inborn error of metabolism; SD Standard deviation.