Child with bouts of laughter, what should be the possible diagnosis ?

ANGELMAN SYNDROM/Happy puppet syndrome Bouts of laughter, intellectual disability, cerebella ataxia and severe developmental delay, Malformations of the skull and facial bones, seizures RUSSELL SILVER SYNDROME - Sho stature , Triangular facies PRADER WILLI SYNDROME - Obesity, Feeding difficulty, Intellectual disabilities FRAGILE X SYNDROME as- XL dominant ,Elongated face, large ears, large testis