“Diagnosis of Rett syndrome is based upon clinical criteria;  A clinician should consider Rett syndrome when slowing of head growth is observed after birth. In most cases, the correct diagnosis can be made through a blood test(s) to identify the mutation of the MECP2 gene. But since the MECP2 mutation can also be found with other disorders, this finding alone is not enough to make a conclusive diagnosis of Rett syndrome.”

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