Noonan's syndrome. IQ and specific disabilities

Area of Science:

• Neurodevelopmental Disorders
• Genetics
• Pediatric Neurology

Background:

• Noonan syndrome (NS) is a genetic disorder with variable clinical manifestations.
• Cognitive abilities in NS patients often range from normal to intellectual disability.
• Previous studies highlight cognitive variability, but specific patterns of disability require further investigation.

Purpose of the Study:

• To assess the spectrum of intellectual functioning in male patients with Noonan syndrome.
• To identify the presence and nature of specific cognitive deficits, particularly verbal and praxic (visual-constructional) abilities.
• To emphasize the importance of detailed cognitive assessment for academic placement in NS.

Main Methods:

• Evaluated eight male patients diagnosed with Noonan syndrome, aged 13–26 years.
• Administered IQ tests to determine overall intellectual functioning.
• Analyzed individual performance to identify specific verbal and praxic (visual-constructional) disabilities, considering visual acuity.

Main Results:

• IQ scores ranged from 64 to 127, with a median of 102, indicating wide variability.
• Overall IQ scores masked specific cognitive impairments in several cases.
• Four patients exhibited major praxic disability, and one had substantial verbal disability; three of the praxic deficits were unrelated to visual impairment.

Conclusions:

• Apparent general intellectual disability in Noonan syndrome warrants further investigation for specific cognitive deficits.
• Detailed neuropsychological assessment is crucial for understanding individual cognitive profiles in NS.
• Tailored academic placement based on specific strengths and weaknesses is recommended for individuals with Noonan syndrome.