Genetics of Neonatal Hypoglycaemia

Hypoglycaemia is the most common metabolic health complication in newborns. Persistent and severe hypoglycaemia in a neonate is correlated with morbidity and could represent an early clinical manifestation of an endocrine or metabolic, genetically determined disorder. Besides this, the most common reason for neonatal hypoglycaemia is the inmature liver storage of glucose seen in preterms or children born intrauterine growth retarded. The genetic determination of hypoglycaemia is gene- and allele- heterogeneous, and thus complex to diagnose. Nevertheless its contribution to brain damage and intellectual disability in children provides a strong rationale for comprehensive and rapid testing. Hypoglycaemia may contribute directly to the phenotype of various genetic syndromes but because of their rarity, it has been not always included in differential diagnosis and its frequency has been underestimated. In clinical practice but also with the growing attention to improved neonatal helathcare and to neonatal genetic screening programmes, the detailed classification of genotype to phenotype is of great importance. This review provides a catalogue of syndromic forms of neonatal hypoglycaemia.