Hi,
I have prepared the birth chart and following is the analysis of the same :
Lagna Lord : Saturn
Lord of eighth house : Mercury
Planets placed in eighth house : Rahu and Moon
Current Mahadasha : Mars ( till April 2020 )
Analysis :
Your grandson was born in pratyandarsha of Mercury and mercury own the eighth house where Rahu and Moon is placed. Conjunction of Rahu and Moon is not a good placement in birth chart specially in eighth house. This conjunction increased the tendency of diseases in the native as we have seen that this house is owned by Mercury so it create problem with the voice of the native.
The next mahadasha is of Rahu , so it will create more trouble to the native. Better you take your grandson to shiv mandir on every saturday and keep a pet dog at your home. Chant mahamriyunjaya mantra daily 108 times while he is sleeping this will definitely help him.