Aicardi-Goutieres syndrome (AGS) is a very rare genetic condition. A 16-month old girl one of twin, was born from consanguineous marriage with microcephaly, global developmental delay, hypertonia, failure to thrive has been presented here. Extensive lab work and MRI images suggested differential diagnosis of Aicardi-Goutieres, megalencephalic leukoencephalopathy with subcortical cysts, CMV TORCH intrauterine infection. The molecular testing for Aicardi-Goutieres syndrome (AGS) was performed which revealed an apparent homozygous deletion of exons 14 and 15 in the SAMHD1 gene. These exons repeatedly failed to amplify for sequence analysis which is consistent with a diagnosis of Aicardi-Goutieres syndrome. Symptomatic management and Genetic counselling done.