Newborn screening before starting breastfeeding

What it is

2 diseases must be screened before breast feeding is given: galactosemia and phenylketonuria. In both the baby is well at birth.

They sit inside the wider newborn screen: newborn metabolic disorders by a heel-prick blood test in all newborns shortly after birth, phenylketonuria by heel-prick screening in the neonatal period, congenital hypothyroidism by a TSH/T4 newborn screen, and hearing loss by otoacoustic emissions or ABR at birth. So the disease to name when the question is what is screened before breast feeding is given is galactosemia, with phenylketonuria beside it.

How it presents

Galactosemia is galactose-1-phosphate uridyl transferase (GALT) deficiency. It shows as poor feeding, vomiting, jaundice and hepatomegaly when the baby is fed milk. The findings that name it are hypoglycemia, conjugated hyperbilirubinemia, hepatomegaly, E. coli sepsis, cataracts and vomiting with failure to thrive after feeding.

A 4 days old boy born to consanguineous parents after an uneventful pregnancy is started on breast feeding with no concern, then has recurrent vomiting, avoids feeding and turns less responsive. He is lethargic, moderately dehydrated, jaundiced with a clouded eye and hepatomegaly, with hypoglycemia, deranged LFT and pre-renal azotemia.

Phenylketonuria is a phenylalanine hydroxylase (PAH) defect, inherited autosomal recessive, so phenylalanine increases in the body, and with it phenylpyruvate and phenylacetate. Symptoms are often absent at birth and it is detected by screening; what it brings is intellectual disability, seizures, a musty odor, which comes from the phenylacetate, and fair skin and hair.