Reversal was required where probate court granted guardianship without referral to CPS. Mark G. filed an application under Probate Code section 1513 to obtain a guardianship of his four-year-old developmentally delayed autistic nephew, the son of his brother. The minor and his father were living in filthy and unsafe conditions, as father had mental problems which included hoarding. Father opposed the guardianship due to Mark’s criminal history and substance abuse. The juvenile court found that returning the minor to father would be detrimental to him and granted the guardianship. The appellate court reversed and remanded. The probate court was required to make a referral to CPS because Mark’s statements concerning the minor’s circumstances amounted to an allegation that father was unfit. The Probate Code is intended to work together with dependency laws as a cohesive statutory structure. The case should have been referred to CPS for further investigation to determine whether dependency proceedings should have been initiated. The referral to CPS was mandatory. The probate court’s failure to refer the case to CPS was not harmless error.