Cerebral Palsy: Causes, Not Genetic Inheritance

Cerebral palsy (CP) is not a genetic disorder. It is a group of permanent movement and posture disorders caused by non-progressive brain injury or maldevelopment occurring before, during, or shortly after birth (prenatal, perinatal, or early postnatal period).

Key Risk Factors

• Prematurity and low birth weight: The strongest risk factor; <28 weeks gestation and <1500 g carry the highest risk.
• Perinatal hypoxia-ischemia: Birth asphyxia, placental abruption, umbilical cord complications.
• Intrauterine infections (TORCH): Toxoplasmosis, rubella, CMV, herpes simplex, Zika; maternal fever/inflammation can trigger fetal brain injury.
• Neonatal stroke or intracranial hemorrhage: Especially periventricular hemorrhage in preemies.
• Severe neonatal jaundice (kernicterus): Unconjugated bilirubin crosses the blood-brain barrier, damaging basal ganglia.
• Birth trauma: Instrumental delivery, excessive force.
• Multiple gestation: Twin-twin transfusion syndrome, prematurity.

The Genetic Role: Nuanced but Not Primary

• Rare genetic syndromes (e.g., hereditary spastic paraplegia, metabolic disorders) can mimic CP or increase susceptibility to brain injury from insults that would otherwise be tolerated.
• CP itself is not inherited in a Mendelian pattern (no single "CP gene").
• Genetic testing (chromosomal microarray, exome sequencing) is sometimes used to rule out CP mimics when the clinical picture is atypical or there's a family history of neurological disorders.

Management and Outlook

Early intervention—physical, occupational, and speech therapy; orthotics; medications (baclofen, botulinum toxin for spasticity); and selective dorsal rhizotomy or orthopedic surgery in select cases—maximizes function and independence. However, these interventions do not reverse the underlying static brain injury.

CP is a clinical diagnosis based on history, examination, and neuroimaging (MRI). Understanding its acquired nature directs focus toward prevention (prenatal care, preterm birth reduction, neuroprotection) and early supportive care.