A 2-year-old boy developed normally until age 20 months, after which he lost previously acquired language, social skills, bowel and bladder control, and purposeful hand use. He now exhibits stereotypic hand-wringing movements. Which diagnosis is most likely?

• A Autism spectrum disorder
• B Landau-Kleffner syndrome
• C Childhood disintegrative disorder
• D Rett syndrome ✓

Explanation

Rett syndrome, caused by MECP2 gene mutations, is characterized by apparently normal early development followed by regression between 6 and 30 months, with loss of purposeful hand skills, stereotypic hand-wringing or hand-washing movements, loss of social engagement, and severely impaired language. Childhood disintegrative disorder involves regression after at least 2 years of normal development. Rett syndrome was removed from DSM-5 as a separate diagnosis.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.