A rare genetic disorder causing persistent severe neonatalhypoglycaemia the diagnostic workup.

We report a case of familial glucocorticoid deficiency (FGD), a rare genetic autosomal-recessive disorder with typical hyperpigmentation of
the skin and mucous membranes, severe hypoglycaemia, occasionally leading to seizures and coma, feeding difficulties, failure to thrive
and infections. A newborn child was admitted, on his second day of life, to our neonatal intensive care unit because of seizures and
respiratory insufficiency. Hyperpigmentation was not evident due to his Senegalese origin. The clinical presentation led us to consider a
wide range of diagnostic hypothesis. Laboratory findings brought us to the diagnosis of FGD that was confirmed by molecular analysis
showing an MC2R:p.Y254C mutation previously reported as causative of type 1 FGD and two novel heterozygous non-synonymous singlenucleotide
polymorphisms in exon 2 and 3 of melanocortin 2 receptor accessory protein-α, whose role in the disease is currently
unknown. The importance of an early collection and storage of blood samples during hypoglycaemic event is emphasised.