My Grandson Has Fat, Bigger Then Usual Feet For A

my grandson has fat, bigger then usual feet for a child, they sweat alot more then normal. All his toes are straing across, there are no toes one bigger then the other. He drools more then the average child, he's been drooling since the age of 2 months, he's six month. He's constantly sweating. He was daignosed with Acid Reflux. I'm just wondering if these maybe symptoms of something we aren't seeing. I have 4 other grandchildren and the don't or have had these problems with out the usual sweating (it's hot day)
or drooling (teething)