Thank you for your query.
Before a correct advice can be provided, it will be prudent to know what was the cause of jaundice
at 4-5 months of age and what treatment was given? Both enzymatic causes and structural anomalies of the hepatic ducts can cause delayed jaundice in a child at this age.
By the description provided by you it appears that the child had high jaundice at birth which can affect the brain if the level of unconjugated bilirubin
is more than 20 mg%. This condition is known as kernicterus
and the motor functions of the child are affected.
I hope I have answered your query to your satisfaction.