i believe you're thinking of angelman syndrome. however i want to caution you that an infant of just three weeks of age is far too young to diagnose with this condition. angelman syndrome is a genetic disorder. it's true one of the hallmarks of the disorder is a happy disposition. however the main characteristics of this disease are developmental delays learning disabilities the inability to speak and poor coordination of voluntary movements. obviously a 3-week-old baby is much too young to assess for any of these symptoms. a three week old baby is not yet expected to sleep through the night. regarding not eating well this is an issue that should be discussed with the baby's pediatrician. he or she is in the best position to judge whether or not the baby is getting adequate calories. many three week old babies smile when spoken to. this is a time to enjoy your grandbaby as she responds to stimulation like being spoken to gently blown on and cuddled. try not to jump to the conclusion something is wrong with your grandbaby. let the mother and the doctor determine whether or not your little angel is gaining weight and developing appropriately to her age. best wishes to you!
my 3 week old granddaughter does not eat well or sleep well. however she smiles widely when spoken too. i saw an episode on mystery diagnosis that seems similar to her. it was a while ago and i didn't think much of it but i remember them saying the first clue was the "happy infant' that they were very young and it ended up being a rare and i believe neurological disease. she does also have problems with her kidney tubes not developed fully and the ped. was concerned she was not gaining enough weight in the proper time frame. i cant find the episode to find the name of the disease. can u help?