A patient of 9 yrs presented with delayed milestoes in all 4 domains with mental motor age of 6 months.There was h/o birth asphyxia. difficulty in swallowing due to pseudobulbar palsy resulting in recurrent aspiration pneumonia. His weight was 30% of expected and height was 70% of expected.o/e had social smile and was able to recognise mother.was able to roll over and that was the only mobility.No speech except vocalisation.had gross hypotonia with dislocatable shoulder joints.There was no head control.Power was grade 3 in all limbs.sensory system was normal.Deep Jerks were exagerated.Kindly give the differntial diagnosis. I find difficult to accept this much hyotonia only with birth asphyxia.increased jerks are another astonishing finding.Thanks