Patient presents with symptoms consistent with a diagnosis of Pervasive Developmental Disorder, now generally recognized as Autism Spectrum Disorder (ASD).  Clinical presentation includes significant impairment in social interaction, communication deficits, and restricted, repetitive patterns of behavior, interests, or activities.  Onset of these symptoms occurred in early childhood, impacting developmental trajectory.  Specific observations include difficulties with reciprocal social interaction, such as limited eye contact, challenges understanding nonverbal cues, and difficulty developing and maintaining peer relationships.  Communication impairments manifest as delayed language development, echolalia, and pragmatic language difficulties.  The patient exhibits repetitive behaviors including hand flapping and insistence on sameness.  Differential diagnosis considered intellectual disability, language disorder, and attention-deficit hyperactivity disorder (ADHD).  Assessment included clinical observation, developmental history obtained from parent report, and standardized autism diagnostic tools such as the Autism Diagnostic Observation Schedule (ADOS).  Based on the comprehensive evaluation, the diagnosis of Pervasive Developmental Disorder, consistent with the DSM-IV-TR criteria and now understood within the broader framework of Autism Spectrum Disorder per DSM-5, is confirmed.  Treatment plan recommendations include referral for Applied Behavior Analysis (ABA) therapy, speech and language therapy, and occupational therapy.  Prognosis, functional impact, and medical necessity for ongoing therapeutic interventions will be continuously reassessed and documented.  ICD-10 code F84.9 (Pervasive Developmental Disorder, Unspecified) was used for billing purposes, recognizing the transition to DSM-5 diagnostic criteria and coding practices within current healthcare settings.  Family education and support services are integral components of the treatment plan.