Rett syndrome before regression: A time window of overlooked opportunities for diagnosis and intervention

Area of Science:

• Neuroscience
• Developmental Biology
• Genetics

Background:

• Rett syndrome (RTT) is a rare neurodevelopmental disorder affecting females, characterized by initial normal development followed by regression.
• Current diagnosis relies on clinical presentation around 2 years of age, but early signs are increasingly suspected.

Purpose of the Study:

• To review existing literature on the pre-symptomatic stage of Rett syndrome.
• To investigate early behavioral, physiological, and brain abnormalities in patients and animal models.
• To challenge the traditional concept of disease regression.

Main Methods:

• Systematic literature review of studies on Rett syndrome.
• Analysis of pre-symptomatic abnormalities in human patients and animal models.
• Focus on behavioral, physiological, and neurobiological alterations.

Main Results:

• Subtle but consistent impairments precede overt RTT symptoms, potentially originating during embryogenesis.
• Some early abnormalities may be transient, indicating developmental compensation.
• Evidence suggests RTT may not be characterized by a sudden regression but by early-onset, subtle deficits.

Conclusions:

• The concept of regression in Rett syndrome needs re-evaluation.
• Early pathological markers are likely present before clinical manifestation.
• Systematic developmental analyses are needed for early diagnosis and targeted interventions.