A female child had normal developmental milestones until 6–8 months of age, after which she developed progressive regression in language, social interaction, and adaptive behavior. The regression was accompanied by loss of purposeful hand use replaced by stereotyped repetitive hand-wringing or clapping movements, and deceleration of head circumference growth. Which of the following is the most likely diagnosis?

1. A

   Childhood disintegrative disorder

2. B

   Down syndrome

3. C

   Asperger syndrome

4. D

   Rett syndrome

Appeared in: AIIMS Manglagiri NO - 2019

Explanation

• The clinical scenario describes the hallmark features of Rett syndrome, a neurodevelopmental disorder primarily affecting females.
• Key diagnostic criteria include a period of normal development for the first 6-18 months, followed by a partial or complete loss of acquired purposeful hand skills and spoken language.
• The development of characteristic stereotyped hand movements, such as wringing, clapping, or mouthing, is a classic sign that replaces purposeful hand use.
• Another core feature is the deceleration of head growth, leading to acquired microcephaly.
• The regression in social interaction, language, and adaptive behavior after an initial period of normal milestones strongly points towards this diagnosis over other developmental disorders.

Why Other Options Were Wrong

• Option A: The age of onset is incorrect. Childhood disintegrative disorder is characterized by developmental regression after at least two years of normal development.
• Option B: Down syndrome is a congenital chromosomal disorder with features typically present from birth. It does not present with a period of normal development followed by regression.
• Option C: Asperger syndrome (now part of Autism Spectrum Disorder) involves impairments in social interaction and restricted interests, but not the profound regression of motor skills, loss of purposeful hand use, or deceleration of head growth seen in Rett syndrome.

Related Visual

Clinical Relevance

• Nursing practice connection: Safe nursing care depends on performing Neurodevelopmental Disorders in the correct sequence, documenting the action clearly, and monitoring for the expected response.
• Nurses play a crucial role in identifying developmental red flags during well-child visits. Recognizing the unique pattern of regression in Rett syndrome can lead to earlier diagnosis and intervention.
• Management of Rett syndrome is supportive and multidisciplinary, focusing on managing symptoms like seizures, GI issues, and scoliosis, and providing physical, occupational, and speech therapy to maximize function and quality of life.
• Rett syndrome is most commonly caused by a mutation in the MECP2 gene on the X chromosome. Genetic counseling is important for affected families.

How to Approach the Question

• First, carefully analyze the patient's demographic and timeline: a female child with normal development until a specific age (6-8 months).
• Identify the key clinical features described: progressive regression, loss of purposeful hand use, stereotyped hand movements (wringing/clapping), and decelerated head growth.
• Systematically evaluate each option against this cluster of symptoms.
• For 'Rett syndrome', recognize that this combination of features represents the classic presentation.
• For 'Childhood disintegrative disorder', note the discrepancy in the age of onset (CDD is >2 years).
• For 'Down syndrome' and 'Asperger syndrome', recognize that their core features do not include this specific pattern of regression and motor skill loss.

Concept Tested & Keywords

• Concept Tested: Neurodevelopmental Disorders
• Stem keywords: female child, normal developmental milestones, 6–8 months, progressive regression, loss of purposeful hand use, stereotyped repetitive hand-wringing, deceleration of head circumference growth
• Lead-in keywords: most likely diagnosis
• Clinical cues: The combination of early normal development, followed by regression, loss of purposeful hand skills, and specific stereotyped hand movements in a female child is a classic vignette for Rett syndrome.

Question ID

Q-NoQ1AvEAuxDcAcdmyge5

Copy ID

Reference Book

E6 Kaplan Sadock's Synopsis of Psychiatry-2022 (pp 1-3768 of 3768) pp. 391-393, 335-337