Hypertonia, Microcephaly and Hyperkalaemia in a Neonate: Coexistence of Neurodevelopmental Disorder and Adrenal Insufficiency

In neonates with more than one clinical abnormalities, we always look for a unifying diagnosis that explains the entire clinical presentation. In rare instances, two conditions can co-exist. Here, we report a neonate born out of consanguineous marriage presenting at 48 hours of life with microcephaly, encephalopathy, hypertonia. He had excessive weight loss, persistent hyperkalaemia, shock and elevated level of 17- hydroxyprogesterone. Steroids were started for adrenal insufficiency. Magnetic resonance imaging (MRI) of the brain revealed T2 hyperintensity of cerebral white matter, hypomyelination and parenchymal volume loss causing microcephaly. Clinical exome sequencing (CES) revealed a pathogenic homozygous missense variation of CYP21A2 gene responsible for congenital adrenal hyperplasia and also the presence of a homozygous missense variant of unknown significance (VUS) of VARS gene implicated in neurodevelopmental disorder with microcephaly, seizures, and cortical atrophy (NDMSCA). Baby was neurologically abnormal at discharge. In the setting of consanguinity, there is a possibility of two genetic conditions. Clinical exome sequencing test is useful in demystifying the diagnosis in complex clinical presentation.