Introduction: ASD is a neuro-developmental disorder characterised by social communication deficits, repetitive behaviour & sensory issues. Most ASD cases are non-syndromic (75%), while others have a known genetic-metabolic aetiology (25%). We report 5 cases with pre-existing disease presenting with ASD & discuss the possible aetiology.

Methods: Case series of 5 ASD cases with underlying disorder.

Case Description: Case 1- 7 years old boy with global developmental delay & dysmorphism suggestive of Prader-Willi syndrome (PWS) presented with ASD.  FISH for PWS confirmed the diagnosis. Case 2: 4 years old boy diagnosed & treated for Neuroblastoma with Opsoclonus-Myoclonus syndrome (OMS) at 15 months of age. He presented with ASD features at 4 years of age. Case 3 – 2.5 years old boy presented with Global delay, ASD features & incoordination. His urine GCMS for organic acids was suggestive of Succinate semialdehyde dehydrogenase (SSADH) deficiency. Case 4 – 4 years old girl presented with coarse facial features, short stature & global delay along with ASD features.  Her urinary screen for Mucopolysaccharidosis (MPS) is positive. Case 5 – 3 years old boy presented with ASD. He had hemiplegia after minor trauma & was diagnosed with mineralising angiopathy at 1.5 years of age on neuro-imaging.

Results & Conclusion:  PWS, MPS & SSADH deficiency are known causes of ASD, but its correlation with OMS & Mineralising angiopathy is not known. We suggest that children with underlying neurological disorder with concerns of social communication deficit should be screened for ASD.

Reference: Griesi-Oliveira K eta al. Einstein 2017;15(2):233-238.