Complex sentence: Not all Robertsonian translocations result in genetic disorders; "balanced" Robertsonian translocation results in no loss or gain of genetic material, and results in no ill-effects on health.
Split into simpler sentences: Not all Robertsonian translocations result in genetic disorders, however. A "balanced" Robertsonian translocation results in no loss or gain of genetic material, and results in no ill-effects on health.