A Case Report of Cantu Syndrome Highlighting the Importance of Genetic Sequencing in Addition to Radiological Testing

An infant initially suspected to have glutaric aciduria was later diagnosed with Cantu syndrome and found to be a carrier of Congenital Disorder of Glycosylation Type 1j. This case involved a five-month-old male infant with Atrial Septal Defect (ASD) and Patent Ductus Arteriosus (PDA) who was under treatment and admitted with a history of recurrent respiratory tract infections, developmental delay, and dysmorphic facies. A metabolic workup was performed. Computed Tomography (CT) brain showed features suggestive of glutaric aciduria; however, MRI brain revealed tortuosity of the cerebral vessels, which was inconsistent with that diagnosis. Hence, Whole Exome Sequencing (WES) was performed. The WES revealed a pathogenic variant in the ABCC9 gene, which is pathognomonic of Cantu syndrome. It also showed a pathogenic variant in the DPAGT1 gene, diagnostic of Congenital Disorder of Glycosylation Type 1j. This is the first reported case in which both mutations were identified in the same patient. WES was subsequently performed for the parents, and the infant’s father was found to have heterozygous pathogenic variants in both genes identified in the proband. This study emphasises the importance of genetic sequencing in establishing an early and accurate diagnosis, thereby enabling disease-specific novel treatment approaches and long-term follow-up.